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Table of Content
Smoke detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
The ram air ventilation system . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
21-00 Air Conditioning general
The emergency ram air valve . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Air conditioning packs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Valve actuator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Re circulation fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Emergency ram air check valve . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Gasper ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Ram air valve operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Trim air (optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Smoke removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Electronic compartments ventilation . . . . . . . . . . . . . . . . . . . . . . . . 5
Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
21-21 Avionics compartment
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
21-20 Air conditioning distribution
Forward avionics compartment fan . . . . . . . . . . . . . . . . . . . . . . . . .3
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Forward avionics compartment ventilation ducts . . . . . . . . . . . . . . .3
Air supply to the flight deck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Forward avionics compartment flow sensor . . . . . . . . . . . . . . . . . . .3
The Cabin air distribution system . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
The distribution duct system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The middle avionics bay fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Fuselage thermal acoustic insulation . . . . . . . . . . . . . . . . . . . . . . . . 7
Middle avionics compartment fan . . . . . . . . . . . . . . . . . . . . . . . . . .7
Fuselage drain valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Middle avionics compartment fan (2-speed) . . . . . . . . . . . . . . . . . .7
The Mixer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Middle avionics compartment flow sensor . . . . . . . . . . . . . . . . . . . .7
The gasper ventilation system . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Middle Avionics Compartment Fan Operation . . . . . . . . . . . . . . . . .9
Cabin air re circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
The re circulation fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Re circulation fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Re circulation fan filter (HEPA-type) . . . . . . . . . . . . . . . . . . . . . . . 17
Issue: Feb06
Revision: 00
21-27 Forward cargo compartment
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Forward cargo compartment fan . . . . . . . . . . . . . . . . . . . . . . . . . . .3
FOR TRAINING ONLY
Reproduction Prohibited
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Page I
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Forward cargo compartment check valve . . . . . . . . . . . . . . . . . . . . 3
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Forward cargo compartment shut off valve . . . . . . . . . . . . . . . . . . . 3
The cabin pressure control system . . . . . . . . . . . . . . . . . . . . . . . . .3
Forward cargo compartment ventilation ducts . . . . . . . . . . . . . . . . . 3
The pressurization control panel . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
The cabin pressurization controller . . . . . . . . . . . . . . . . . . . . . . . . .7
ECS Built-in Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Positive Differential Pressure Limitation . . . . . . . . . . . . . . . . . . . . .7
Auto pressure control loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
21-28 Electronic Rack Ventilation System
The Cabin Pressure Control System modes . . . . . . . . . . . . . . . . .11
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Climb and Cruise modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
System description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Descent and Abort modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Airflow Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Manual mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Built-in Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Ventilation ducts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Outflow valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Shutoff valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
The positive pressure relief valve . . . . . . . . . . . . . . . . . . . . . . . . .23
Maintenance Test Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Negative pressure relief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Monitoring Panel (LEDS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
EICAS indications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Fan Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
21-40 Heating
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Ground Shutoff Valve Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Floor panel heaters operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Vent Shutoff Valve Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
The floor panels heaters construction . . . . . . . . . . . . . . . . . . . . . . .5
Air Flow Switch Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Maintenance Test Panel Operation . . . . . . . . . . . . . . . . . . . . . . . . 13
21-50 Cooling
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
21-30 Pressurization
Issue: Feb06
Revision: 00
ECS pack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
FOR TRAINING ONLY
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The flow control valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
The two cabin zone configuration . . . . . . . . . . . . . . . . . . . . . . . . . .7
The flow sensing venturi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Trim modulating valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Venturi Delta-P sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Automatic temperature control . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Air conditioning pack flow controls . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The dual heat exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Fan bypass check valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
21-MEL (Example)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
The air cycle machine components . . . . . . . . . . . . . . . . . . . . . . . . 11
Air cycle machine operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Condenser/Reheaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Water collectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Water spray nozzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
The bypass valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Add heat, and low limit bypass valve . . . . . . . . . . . . . . . . . . . . . . . 19
The low limit bypass valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Add heat valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Temperature sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
ECS Off Request . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Pack related messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
21-60 Temperature control
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Zone Temperature Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Cockpit zone control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Single cabin zone configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Issue: Feb06
Revision: 00
FOR TRAINING ONLY
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Issue: Feb06
Revision: 00
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190
21-00 Air Conditioning general
Introduction
The Environmental Control System (ECS) provides air conditioning for the
flight deck and passenger cabin, filtered cabin air re circulation, conditioned
air supply for gaspers, fan air cooling for avionics and emergency ram air
ventilation for flight deck smoke clearance.
The ECS provides cargo bay ventilation. The cargo bay ventilation system
is optional.
• Two identical ECS packs which condition fresh bleed air for cabin and
flight deck heating and cooling
• Optional trim air system to provide two cabin zone temperature control
• Flow control valves to provide accurate modulation of pack air flow, and
all associated valves and sensors used for system built in test
• Avionic fan control and cargo compartment ventilation
• Cockpit smoke removal
• Provides environmental control system flow rate data used by the cabin
pressure control system to anticipate changes in cabin pressure.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-00
Page 1
Figure 1: The air conditioning system
Issue: Aug05
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Chapter 21-00
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190
Air conditioning packs
Trim air (optional)
Two ECS packs are installed in the wing-to-fuselage fairing. The AMS controller controls the bleed airflow to each pack independently, through the respective pack flow control valve (FCV). Engine # 1 supplies bleed air to the
pack # 1 while engine # 2 supplies bleed air to pack # 2. A single pack is
capable of keeping adequate cabin/cargo hold pressurization and temperature. Single engine bleed can supply both ECS packs using the cross bleed.
The trim air system controls the amount of hot bleed air from the pack 2 into
the mixer for independent control of forward and aft cabin zones temperatures. The trim air system is used for temperature control improvement.
Re circulation fans
Re circulated air from the passenger cabin and cockpit is ducted to the mixing manifold via two re circulation fans located in the pressurized section of
the airplane.
The re circulation fans draw air from the re circulation bays and impel the air
back into the flight deck and cabin distribution system.
The total flow entering the cockpit and the passenger cabin is made up of
approximately 52% fresh air and 48% of re circulating air.
The re circulation fans are commanded off when DUMP button is pressed or
smoke is detected in the re circulation bay.
Gasper ventilation
The gasper air distribution system provides air to each pilot and passenger
positions.Air flowing from the mixing manifold through the gasper ducts supplies the gasper ventilation system.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-00
Page 3
Figure 2: Air conditioning block diagram
COMPARTMENT
RECIRCULATIOM
FILTER
RECIRCULATION
FAN FILTER
F
FAN
E-BAY
FORWARD
RECIRCULATION FAN
FLIGHT DECK
FROM LEFT
BLEED SYS
LEFT
ECS
PACK
T
T
F
F
F
F
T
F
E-BAY
MID
FORWARD CABIN
T
F
F
GROUND CONN.
MIXER
F1
SAFETY
VALVES
CABIN
P T
MUFFLER
OUTFLOW
VALVES
P T
MUFFLER
FROM RIGHT
BLEED SYS
T
RIGHT
ECS
PACK
AFTCABIN
FROM RIGHT
BLEED SYS
PRESSURIZED
UNPRESSURIZED
TO GASPERS
RECIRCULATION FAN
RECIRCULATION
FAN FILTER
FAN
FILTER
COMPARTMENT
RECIRCULATIOM
Issue: Aug05
Revision: 00
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190
Electronic compartments ventilation
Emergency ram air ventilation
Forward electronic bay (E-Bay)
The forward e-bay comprises three fans, which provide forced cooling air for
# 1 Secondary Power Distribution Assembly (SPDA 1), Emergency Integrated Control Centre (EICC) and all other avionics located in this e-bay. The
fans draw air from the cockpit and expel air toward the underfloor re circulation bay. A flow sensor is used for fan/flow health monitoring to ensure forward e-bay flow requirements.
The pack 1 ram air ventilation consists of a ventilation valve installed in
emergency ram ducting that connects the ram air duct to the pack 2 outlet
ducting. The emergency ram air valve is commanded open any time the airplane is in flight and both air conditioning packs are commanded OFF or
failed OFF and the airplane’s flight altitude is less than 25000 ft.
The pack 2 ram air ventilation consists of a check valve installed in the emergency ram air ducting that connects the ram air duct to the pack 2 outlet
ducting. The emergency ram air check valve does not require electronic control. The emergency ram air check valve will be open whenever the pressure
in the ram air circuit is greater than cabin pressure.
Centre electronic bay (E-Bay)
The centre e-bay comprises three fans, which provide forced cooling air for
the centre e-bay electronics, Left Integrated Control Centre (LICC), Right Integrated Control Centre (RICC) and SPDA 2. The fans draw air from the rear
cabin return and expel it toward the underfloor re circulation bay.
Flow sensors are used for fan/flow health monitoring.
Forward cargo bay ventilation (Optional)
The ECS provides ventilation for live animals in the forward cargo bay.
This optional system contains a fan on the side of the bay to provide underfloor re circulation air into the bay. The system also contains a shutt off valve
at the outlet of the bay that closes in the event of fire and thus preventing
halon from leaving the bay. In addition, in the event of fire, forward cargo
compartment fans are commanded OFF to prevent halon from entering the
cabin.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-00
Page 5
Figure 3: Passenger-cabin zone temperature control block diagram
TEMPERATURE SETTING
LOW
C
HIGH
OFF
DOOR ZONE TEMPERATURE
H
ON
CEILING
BRIGHT
DIM
SIDEWALL
BRIGHT
DIM
EMERGENCY LIGHT
ON/
ARMED
TEST
SPDA 1
DISCRETE I / O MODULE
(SDS 24-61)
(MPP 24-61-05)
(WM 24-61-50)
GALLEY MASTER
ON
ON
FWD
ENTRANCE
FWD GALLEY
AREA
BRIGHT
PANEL LIGHTS
BRIGHT
DIM
TEST
DIM
COURTESY LIGHT
RESET
OFF
AUTO
LAVATORY SMOKE TEST
SPDA 2
AMS CONTROLLER
INPUT / OUTPUT MODULES
(SDS 21-61)
(MPP 21-00-01)
(WM 21-61-50)
SPDA 2
AMS CONTROLLER
PROCESSOR MODULES
(SDS 21-61)
(MPP 21-00-01)
(WM 21-61-50)
SPDA 2
AMS CONTROLLER
MOTOR DRIVER MODULES
(SDS 21-61)
(MPP 21-00-02)
(WM 21-61-50)
ENABLED
CABIN TEMPERATURE
CABIN LIGHTING
ON
TEMPERATURE SETTING
AIR COND / PNEUMATIC
RECIRC
CKPT
PAX
CABIN
LOW
PSU
AFT LH
AFT RH
TEST
RESET
C
HIGH
OFF
FWD
DOOR ZONE TEMPERATURE
C
H
C
ATTND
ATTND CALL
PACK 1
RESET
CABIN LIGHTING
XBLEED
WING 1
START 1
BLEED 1
ON
CEILING
SIDEWALL
FWD
ENTRANCE
BRIGHT
BRIGHT
BRIGHT
DIM
DIM
DIM
EMERGENCY LIGHT
ON/
ARMED
BLEED APU
TEST
FWD GALLEY
AREA
PANEL LIGHTS
BRIGHT
TEST
DIM
COURTESY LIGHT
RESET
OFF
BLEED 2
RECIRCULATION FAN
FAN
(MPP21-24-01)
M F1
PAX CABIN
PSU
AFT RH
TEST
RESET
RESET
AIR COND/PNEUMATIC PANEL
COCKPIT OVERHEAD PANEL
FWD ATTENDANT PANEL
(MPP31-17-04)
(MPP25-25-01)
F
FLIGHT DECK
T
T
AFT LH
ATTND CALL
E-BAY
FORWARD
(MPP21-24-02)
ZONE TEMP
FAN FILTER
FWD
SENSOR SIGNAL
FILTER
LEFT ECS
WING 2
START 2
ON
LAVATORY SMOKE TEST
COMPARTMENT
RECIRCULATION
RECIRCULATION
FROM LEFT
BLEED SYS
GND
CONN
ON
AUTO
PAX CABIN DUCT
TEMP SENSOR SIGNAL
TRIM AIR
BYPASS VALVE SIGNAL
VALVE SIGNAL
PACK OUTLET TEMP. SENSOR SIGNAL
(MPP25-25-02)
ENABLED
GALLEY MASTER
PACK 2
ON
AFT ATTENDANT PANEL
H
CABIN TEMPERATURE
H
T
PACK
(MPP
F
F
SPDA 1
DISCRETE
F
I / O MODULE
21-51-00)
F
FORWARD CABIN
F
E-BAY
MID
T
T
F
F
GROUND CONN.
TRIM AIR
MIXER
F1
(MPP21-20-03)
VALVE
(MPP21-62-05)
SAFETY
VALVES (MPP21-32)
CABIN
P T
MUFFLER
PT
OUTFLOW
VALVE (MPP21-31-02)
(MPP21-62-06)
MUFFLER
FROM RIGHT
BLEED SYS
T
RIGHT ECS
PACK
(MPP
CABIN DUCT
AFTCABIN
T
TEMPERATURE SENSOR
21-51-00)
M F1
RECIRCULATION FAN
PRESSURIZED
UNPRESSURIZED
M F1
(MPP21-24-01)
(MPP21-62-02)
TO GASPERS
FAN
RECIRCULATION
FILTER
FAN FILTER
(MPP21-24-02)
COMPARTMENT
RECIRCULATION
CABIN ZONE
TEMPERATURE SENSOR
PACK OUTLET
PACK BYPASS
(MPP21-51-18)
(MPP21-51-10)
Issue: Aug05
Revision: 00
(MPP21-62-01)
TEMPERATURE SENSOR
VALVE
FOR TRAINING ONLY
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Chapter 21-00
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190
Distribution
The distribution system receives airflow from the re circulation fans, cooling
packs, ram air system and ground equipment and distributes this air to the
cockpit, passenger cabin, gaspers, avionics compartments and forward cargo compartment.
Pressurization control
The aircraft operates at altitudes where the oxygen density is not sufficient
to sustain life. The pressurization control keeps the aircraft cabin interior at
a safe pressure altitude. This protects the passengers and crew from the effects of hypoxia (oxygen starvation).
Cooling
The cooling system receives hot bleed air from the APU (Auxiliary Power
Unit) or engines and supplies conditioned air to the distribution system.
Temperature control
The temperature control system provides independent closed loop temperature control for the cockpit and one or two separate passenger cabin zones.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-00
Page 7
Figure 4: Passenger-cabin zone temperature control block diagram
TEMPERATURE SETTING
LOW
C
HIGH
OFF
DOOR ZONE TEMPERATURE
H
ON
CEILING
BRIGHT
DIM
SIDEWALL
BRIGHT
DIM
EMERGENCY LIGHT
ON/
ARMED
TEST
SPDA 1
DISCRETE I / O MODULE
(SDS 24-61)
(MPP 24-61-05)
(WM 24-61-50)
GALLEY MASTER
ON
ON
FWD
ENTRANCE
FWD GALLEY
AREA
BRIGHT
PANEL LIGHTS
BRIGHT
DIM
TEST
DIM
COURTESY LIGHT
RESET
OFF
AUTO
LAVATORY SMOKE TEST
SPDA 2
AMS CONTROLLER
INPUT / OUTPUT MODULES
(SDS 21-61)
(MPP 21-00-01)
(WM 21-61-50)
SPDA 2
AMS CONTROLLER
PROCESSOR MODULES
(SDS 21-61)
(MPP 21-00-01)
(WM 21-61-50)
SPDA 2
AMS CONTROLLER
MOTOR DRIVER MODULES
(SDS 21-61)
(MPP 21-00-02)
(WM 21-61-50)
ENABLED
CABIN TEMPERATURE
CABIN LIGHTING
ON
TEMPERATURE SETTING
AIR COND / PNEUMATIC
RECIRC
CKPT
PAX
CABIN
LOW
PSU
AFT LH
AFT RH
TEST
RESET
C
HIGH
OFF
FWD
DOOR ZONE TEMPERATURE
C
H
C
ATTND
ATTND CALL
PACK 1
RESET
CABIN LIGHTING
XBLEED
WING 1
START 1
BLEED 1
ON
CEILING
SIDEWALL
FWD
ENTRANCE
BRIGHT
BRIGHT
BRIGHT
DIM
DIM
DIM
EMERGENCY LIGHT
ON/
ARMED
BLEED APU
TEST
FWD GALLEY
AREA
PANEL LIGHTS
BRIGHT
TEST
DIM
COURTESY LIGHT
RESET
OFF
BLEED 2
RECIRCULATION FAN
FAN
(MPP21-24-01)
M F1
PAX CABIN
AFT RH
TEST
RESET
RESET
AIR COND/PNEUMATIC PANEL
COCKPIT OVERHEAD PANEL
FWD ATTENDANT PANEL
(MPP31-17-04)
(MPP25-25-01)
F
FLIGHT DECK
T
T
AFT LH
PSU
ATTND CALL
E-BAY
FORWARD
(MPP21-24-02)
ZONE TEMP
FAN FILTER
FWD
SENSOR SIGNAL
COMPARTMENT
RECIRCULATION
FILTER
LEFT ECS
WING 2
START 2
ON
LAVATORY SMOKE TEST
RECIRCULATION
FROM LEFT
BLEED SYS
GND
CONN
ON
AUTO
PAX CABIN DUCT
TEMP SENSOR SIGNAL
TRIM AIR
BYPASS VALVE SIGNAL
VALVE SIGNAL
PACK OUTLET TEMP. SENSOR SIGNAL
(MPP25-25-02)
ENABLED
GALLEY MASTER
PACK 2
ON
AFT ATTENDANT PANEL
H
CABIN TEMPERATURE
H
T
PACK
(MPP
F
F
SPDA 1
DISCRETE
F
I / O MODULE
21-51-00)
F
FORWARD CABIN
F
E-BAY
MID
T
T
F
F
GROUND CONN.
TRIM AIR
MIXER
F1
(MPP21-20-03)
VALVE
(MPP21-62-05)
SAFETY
VALVES (MPP21-32)
CABIN
P T
MUFFLER
PT
OUTFLOW
VALVE (MPP21-31-02)
(MPP21-62-06)
MUFFLER
FROM RIGHT
BLEED SYS
T
RIGHT ECS
PACK
(MPP
CABIN DUCT
AFTCABIN
T
TEMPERATURE SENSOR
21-51-00)
M F1
RECIRCULATION FAN
PRESSURIZED
UNPRESSURIZED
M F1
(MPP21-24-01)
(MPP21-62-02)
TO GASPERS
FAN
RECIRCULATION
FILTER
FAN FILTER
(MPP21-24-02)
COMPARTMENT
RECIRCULATION
CABIN ZONE
TEMPERATURE SENSOR
PACK OUTLET
PACK BYPASS
(MPP21-51-18)
(MPP21-51-10)
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Revision: 00
(MPP21-62-01)
TEMPERATURE SENSOR
VALVE
FOR TRAINING ONLY
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Chapter 21-00
Page 8
190
Controls
Feet valves selector
The air conditioning controls and indications are:
Purely mechanical control of the feet valves to direct more warm air to the
pilot feet.
Pressurization Control Panel
Controls the pressurization of the aircraft, in AUTO and MANUAL mode.
The mode selector switch facilitates auto, manual mode selection or landing
field elevation settings.
Manual selector enables direct control of the outflow valve.
Dump switch controls auto depressurization of the aircraft.
Air conditioning panel
PACK 1 switch controls the left Cooling Pack (AUTO-OFF)
CKPT knob - Controls the cockpit between 19 and 30 °C.
RECIRC switch - Controls the re circulation system (AUTO - OFF)
PAX CABIN knob - Controls the passenger cabin temperature between 19
and 30 °C.
PACK 2 switch - Controls the right Cooling Pack (AUTO - OFF)
Flight attendant panel
Zone temperature control selector enables attendant cabin temperature
control for zone 1, zone 2 when on the cockpit temperature selector knob the
ATT position is selected.
MCDU data set menu
Take off data set menu enables pilot selection of the ECS system for take
off, ON or OFF.
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Chapter 21-00
Page 9
Figure 5: Indication panels
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Chapter 21-00
Page 10
190
Indications
Four typed of indication are used to monitor Environmental Control System
operation:
• The EICAS provides indication of the pressurization system parameters
• The CAS field display shows warning, caution and advisory messages
• By selecting the MFD menu bar, the ECS synoptic page will provide
system status and indications concerning the environmental control
system
• CMC messages can be viewed on the co-pilot multi-function display by selecting maintenance on the menu bar.
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Chapter 21-00
Page 11
Figure 6: Indications
70. 0
11. 1
CABIN DOOR OPEN
70. 0
ATTCS
11. 1
N1
T
R
T
R
IGN
A B
655°
I TT
655°
90. 0
N2
90. 0
5
FF PPH
5
FU LBS
FQ LBS
5
5
IGN
A B
UP
FUEL QTY
900
900
APU
1
100%
VI B
OI L
DN
1020° C
CABI N
ALT
RATE
P
OFV
64°
PRES
TEMP
FLIGHT CONTROL
HP
LP
LFE
FLAP
Issue: Aug05
Revision: 00
99°
20
38
PITCH
UP
0
15
25
FT
FPM
PSI
DEG
FT
TRIMS
ROLL
SPOILER
-5
-5
- 96. 7
5
1200
YAW
13
45
FOR TRAINING ONLY
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Chapter 21-00
Page 12
190
21-20 Air conditioning distribution
Introduction
The air that is already pressure-regulated by the pneumatic system passes
through the two packs where duct flow and temperature are adjusted to the
required level.
At the packs outlet, temperature sensors monitor duct temperature. Before
the distribution ducts enter the pressurized area, there are ground and ram
air connections. Check valves make sure that there is no back-flow into the
packs.
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Chapter 21-20
Page 1
Figure 1: Air conditioning schematic
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Chapter 21-20
Page 2
190
Air supply to the flight deck
Air supplied to the flight deck is distributed through ducts which run along the
left-hand side of the cabin underfloor area. These ducts then form a loop to
supply the following outlets and areas:
• The raiser will direct air to the rear ceiling outlets,
• from the main and the cross feed supply, air is directed to the side
windows
• The front section of the distribution loop provides display ventilation
through the piccolo duct.
The pilot and first officer positions have handle-actuated butterfly valves that
provide air for foot warming or cooling.
Normally 60% of the mixed air from the left side ECU (Environmental Control
Unit) goes to the cockpit and 40% goes to the passenger cabin through the
mixing manifold (H-duct).
Air passages located in the cockpit floor, under the pilots seats, lateral consoles, and the control column opening let the air return to the re circulation
fans and to the aircraft outflow and pressure relief valves.
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Chapter 21-20
Page 3
Figure 2: Air supply to the flight deck
Left hand side
TR
M
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U
Chapter 21-20
Page 4
190
The Cabin air distribution system
The cabin air distribution system starts at the mixer duct. From this point the
conditioned air is distributed to the gasper system, and to the front and rear
passenger cabin sections. Ducts from the mixer duct direct air to the raisers
and to the upper plenums.
In the gasper system the air exits through the individual outlets above the
passenger seats. For the main distribution system, the air exits above and
below the overhead bins.
Return air passes to the underfloor areas through "DADO" panels located
just above the floor on the fuselage side panels.
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Chapter 21-20
Page 5
Figure 3: Cabin air distribution system
COCKPIT
FWD CABIN
RAISERS
AFT CABIN
Mixer duct
GASPER SYSTEM
FRONT and REAR
PASSENGER CABIN sections
OUTLETS
above the passenger seats
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Chapter 21-20
Page 6
190
The distribution duct system
Bays). The lower part of electronic bays has a non-insulated area of 41.4ft2
for the mid E-Bay, 42.3ft2 for the forward E-Bay and 15ft2 for the aft E-Bay
where neither acoustic nor thermal requirements is needed for occupants.
The distribution duct system has the following main sections:
•
•
•
•
Fuselage drain valve
mixer duct,
cockpit distribution ducts,
cabin front zone distribution ducts and
cabin rear distribution ducts.
The ducts are made of composite material and are protected by adhesive
tape to retain thermal energy.
The ducts are designed to handle temperatures from -40°C to +70°C. (8)
Duct connections are elastomeric sleeves or metal clamps, with ports provided to drain condensation.
The valve assembly consists of a Valve retainer that is fastened to the inner
fuselage wall. A valve housing is inserted (or removed) through this hole
from the aircraft exterior. The valve housing consists of a pre-assembled
valve, which is made of piston-like reciprocating cylinder, a helical compression spring and an aperture-retaining cap.
When the valve is in the OPEN position, collected condensed water (or
whatever other fluid inside the fuselage) and air are free to flow overboard
through cutouts in the valve housing, and out the open valve (between the
upwardly biased valve member and valve seat on the inside surface of the
bottom of the valve housing).
Fuselage thermal acoustic insulation
This material has the following functions:
• Reduce heat transmissions through fuselage for thermal comfort.
• Noise attenuation through fuselage.
It is made of fiberglass and non-hygroscopic blankets. The blankets are involved by a thin, film for mechanical protection and better workmanship,
forming thus a bag. Each bag has a breather, always facing down, to allow
for pressure equalization during aircraft operation. Placement of breather intends to prevent water penetration into the bags.
The pressurized zone is internally insulated with this material, except in the
zones where frame systems installations required differently and in some
case the insulation is not installed for specific purposes (for example E-
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Chapter 21-20
Page 7
Figure 4: The distribution duct system
Ducts
ADHESIVE TAPE
COCKPIT DISTRIBUTION
ducts
CABIN FRONT ZONE DISTRIBUTION
ducts
MIXER duct
CABIN REAR DISTRIBUTION
ducts
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Chapter 21-20
Page 8
190
The Mixer
From the two ECS packs and the two re circulation fans, the air flow is directed to the mix-manifold.
If the optional two-zone system is installed, additional hot air is supplied to
the mix-manifold via trim check valves and trim by-pass valves.
The total air flow entering the flight deck, the cabin compartments and the
gaspers is made up of approximately 50% fresh air and 50% re circulated
air.
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Chapter 21-20
Page 9
Figure 5: Mixer
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Chapter 21-20
Page 10
190
The gasper ventilation system
The gasper ventilation system is supplied by air flowing from the mix manifold through the gasper check valve. The check valve allows air flow to the
front and rear gasper ducts, and through the gasper plenum to the gasper
outlets.
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Chapter 21-20
Page 11
Figure 6: TThe gasper ventilation system
MIXER
FWD CABIN
TO GASPERS
F
F
RECIRCULATON FAN
FAN
RECIRCULATON FAN
FILTER
FILTER
FWD
CARGO
Front gasper ducts
COMPARTMENT
RECIRCULATION
Gasper plen
AFT CABIN
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Rea
r ducts
Chapter 21-20
Page 12
190
Cabin air re circulation
Re circulation of the cabin air is controlled by two re circulation fans. The
fans draw air from the re circulation bay through glass-fibre filter elements
and direct the air back to the mixer duct.
The re circulation fans are single-speed fans driven by three-phase 115/
200V AC motors. The motors contain internal thermal protection circuits to
shut down the fan in case of an over temperature condition.
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Chapter 21-20
Page 13
Figure 7: Cabin air re circulation diagram
C
B
OVERHEAD PANEL
AIR COND/PNEUMATIC PNL
(31-17-04)
RECIRC
SWITCH
E
A
A
(24-61-54)
ON
GND
(ANNUNCIATOR
TEST RELAY
SSM 33-12-80)
MIDDLE AVIONICS COMPARTMENT
SPDA 2
(SSM 24-61-80)
DC BUS 2
D
B
OFF
5V
DIMMER
(SSM 33-12-80)
LICC
MIDDLE AVIONICS COMPARTMENT
LEFT
RECIRCULATION
FAN
D
RECIRCULATION
DUCTS
RICC
(24-61-55)
MIDDLE AVIONICS COMPARTMENT
DC BUS 2
AC BUS 1
AC BUS 2
DC BUS 1
C
B
A
CMD
STAT
C
B
A
SPDA 1
(SSM 24-61-80)
RIGHT
STAT
CMD
RLY
BIT
RECIRC
RECIRC
BIT
RLY
PWR
FEED1
FAN
FAN
FEED1
PWR
SMOKE DETECTOR
(SDS 26-10)
CENTRAL FUSELAGE II
Issue: Aug05
Revision: 00
C
C
CENTRAL FUSELAGE II
SPDA 2
(SSM 24-61-80)
MIDDLE AVIONICS COMPARTMENT
FOR TRAINING ONLY
Reproduction Prohibited
RIGHT
RECIRCULATION
FAN
CHASSIS
SW
THERMAL
THERMAL SW
J9
RLY CMD
J7
RLY STAT
J5
RLY STAT
RLY CMD
J11
D
THERMAL SW
SW
CHASSIS
SMOKE DETECTOR
LEFT RECIRC FAN
(SDS 21-24)
(SSM 21-24-01)
THERMAL
DC GROUND
ALARM OUTPUT
TEST INPUT
POWER INPUT
CHASSIS GND
ARINC 429
RECIRC SW
LEFT
J9
(24-64-50)
J11
CBP
SMK DET
RECIRC FAN
INPUT: 28V/OPEN
5
OUTPUT: 28V/OPEN
COCKPIT
FWD AVIONICS COMPT
RIGHT RECIRC FAN
(SDS 21-24)
(MPP 21-24-01)
E
CENTRAL FUSELAGE II
E
Chapter 21-20
Page 14
190
The re circulation fans
The re circulation fans will be commanded ON whenever the cockpit control
panel switch is in the AUTO position, with two exceptions:
• The fans will be commanded OFF if the Cabin Pressurization Control System dump switch is depressed, or
• if smoke is detected in the re circulation bay.
An EICAS caution message will illuminate in case:
• smoke is detected, or
• if the smoke detector fails.
On the ECS synoptic page the re circulation fans will be indicated in green
when they operate, and in red if they are switched off.
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Chapter 21-20
Page 15
Figure 8: The re circulation fans
OFF
Both Fans OFF
OFF
DUMP SIGNA L FROM CPCS PANEL
OR
RECIRC BA Y SM OKE SIGNA L
OFF
SPDA
RECIRC SMOKE DETECTOR FAILED
AMS
ASSOCIATED PACK OFF
PLA NE IN AIR (WOW FA LSE)
Left (or Right) Fan OFF
AND
OFF
ASSOCIATED PACK OFF
OR
OPPOSITE PACK ON
SPDA
AND
GROUND OPS (WOW TRUE))
AMS
FAN OVERTEM P
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Chapter 21-20
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190
Re circulation fans
The unit consists of a cover assembly and a base plate assembly. The cover
assembly contains holes that permit air and smoke to pass to the internal
chamber of the detector.
The re circulation fan is a 7.25 in diameter single-speed mixed flow fan.
Each aircraft is provided with two re circulation fans.
The fan has the following features:
• The fan wheel is contained in a cylindrical aluminium housing.
• It incorporates a twin flapper check valve design to prevent flow in reverse direction.
• It is driven by a three-phase 115/200 VAC, 400 Hz motor.
• It contains an internal thermal protection circuit which is used to shut
down the fan in the event of an over temperature condition.
Smoke detection will command the Re-Circulation Fans and FWD Cargo
Bay fans off, and command the FWD Cargo Bay Shut Off valve closed.
If smoke in the recirculation bay is detected, a CAS message RECIRC SMK
will be generated.
Re circulation fan filter (HEPA-type)
The re circulation fan filter assembly consists of an 11.5 in diameter cylindrical glass-fiber filter element which is encased in a protective aluminium grid.
The filter is mounted on a bracket in line with both the left and right circulation fans (two per aircraft). The filters cannot be bypassed and become more
efficient with increased service life.
The fan filter has the following features:
• An upper-and-lower composite flange connects the filter element and
protective grid as one assembly.
• A rubber gasket is mounted on the lower flange to provide the sealing
mechanism for installation on the aircraft.
Smoke detector
There is one smoke detector attached below the passenger cabin floor
structure, in the re circulation area, between the re circulation filters.
The smoke detector is a photoelectric type sensor that operates on the principle of light scattering by suspended smoke particles.
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Chapter 21-20
Page 17
Figure 9: Smoke detector
(10 second Delay)
RECIR Smoke Detected
Smoke Detector Fail
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RECIRC SMOKE
RECIRC SMK DET FAIL
FOR TRAINING ONLY
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Chapter 21-20
Page 18
190
The ram air ventilation system
The ram air ventilation system allows outside ambient air to enter the flight
deck and passenger compartment when the air conditioning packs are shut
down.
The system is normally not actuated when packs are operating, and ram air
is passing through the heat exchangers to provide duct cooling.
The ram air system includes a ram air valve installed in the left ram air inlet
duct, and ram air check valve installed in the right ram air duct. The ram air
ventilation valve is a butterfly valve powered by 28 VDC. Micro switches are
provided for position indication.
The manual override feature allows manual opening and closing of the
valve.
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Chapter 21-20
Page 19
Figure 10: Ram air ventilation system
Emergency ram air ventilation valve
Micro switch
Manual override
COMPARTMENT
RECIRCULATION
RECIRCULATION FAN FILTER
FILTER
L.H.
ECS
PACK 1
(FLIGHT
RECIRCULATION FAN
FAN
F
COCKPIT
T
F
F
T
F
F
T
F
T
ambient air
MIXER
F
F
CABIN
SAFETY
VALVES
F
OUTFLOW
VALVE
ECS
PACK 2
(CABIN)
TO GASPERS
F
F
RECIRCULATION FAN
FAN
RECIRCULATION FAN FILTER
FILTER
FWD
CARGO
COMPARTMENT
RECIRCULATION
Emergency ram air heck valve
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Chapter 21-20
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190
The emergency ram air valve
The AMS controller controls the emergency ram air valve.
The emergency ram air valve is commanded open whenever the ram air
valve is commanded open whenever both packs are commanded off or
failed off, the aircraft is below 25000 ft and is weight off wheels.
During smoke removal both packs will be shut off, and therefore the ram air
valve and the ram air check valve will open. EICAS advisory and CMC messages are provided if one or more of the valves fail closed.
The synoptic page shows the ram air valve in green when the valve is open,
and in red when the ram air valve is closed.
Valve
The ram air valve is a 5-inch diameter electrically-actuated butterfly valve.
The valve is opened and closed by a 28 VDC (Volt Direct Current) electric
actuator which rotates a splined butterfly shaft. The ram air valve also contains a manual actuation lever which can be used to manually position the
valve in the event of actuator electrical failure. The valve and actuator require no lubrification or servicing.
of micro switches which are used for valve open/close indication and actuator overtravel protection.
The linear actuator electrical travel is limited by two limit switches, one in the
retracted position and the other in the extended position.
Emergency ram air check valve
The emergency ram air ventilation system allows outside ambient air to enter the cockpit and passenger cabin when the air conditioning pack is shut
down. The emergency ram air check valve is a five inch diameter twin petal
check valve which is located on the right pack ram.air inlet ducting. It is controlled by the AMS controller. The emergency ram air check valve does not
require electronic control. It has:
• Two aluminium check valve petals retained in the check valve housing by
a common hinge pin.
• A wire retention spring used to hold the check valve petals in the closed
position.
• A mechanical bar type stop.
Valve actuator
The ram air valve actuator moves the ram air valve through a movable arm.
When ram air flows to the heat exchanger, the flow to the ram air duct closes, and vice-versa.
The electric actuator utilizes a 28 VDC motor which acts on a worm type
gear and wheel assembly to rotate the valve shaft. The actuator contains
two sets
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Chapter 21-20
Page 21
Figure 11: Emergency ram air valve
Emergency Ram Air
Ventilation Valve
Emergency Ram
Check Valve
FWD
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Chapter 21-20
Page 22
190
Ram air valve operation
The ram air valve is commanded open any time both cooling packs are commanded or failed off. When the ram air valve is commanded open, fresh air
entering the left ram air inlet flows through the valve, bypassing the air conditioning pack, to provide ventilation for the flight deck. This provides additional fresh air ventilation.
The ram air ventilation system is also used for emergency cockpit smoke removal. If there is evidence of smoke in the cockpit, the flight crew will press
the cabin pressure control system DUMP switch.
Upon receipt of the dump switch signal the AMS controller will command
both the left and right pack flow control valve closed. The left and right re circulation fans will be commanded of to eliminate re circulation of cockpit air
flow.
The forward electronics compartment backup ventilation fan will be commanded on to increase ventilation flow through the cockpit area. The ram air
valve will be commanded open.These actions will permit the flow of fresh air
through the ram air valve to clear smoke in the cockpit area. Fresh air will
also flow through the emergency ram air check valve to equalize pressure in
the mixing duct and provide emergency ventilation for the passenger cabin
zones.
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Chapter 21-20
Page 23
Figure 12: Ram air valve operation
Open Ram Valve
Backup E-Bay Fans On
Both Packs Failed Off
Ram Air Flow
ALT< 25K FT
OR
Both Packs Commanded Off
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Chapter 21-20
Page 24
190
Smoke removal
The ram ventilation system is also used for cockpit smoke removal.
Flight crew will depress cockpit DUMP switch as an emergency procedure
for cockpit smoke removal. When the dump switch is depressed the CPCS
(Cabin Pressure Control-System) will depressurize the cabin at a rate of
2000 ft/min. The AMS (Air Management System) controller will then shut
down both air conditioning packs, turn off both re circulation fans and open
the emergency ram air check valve. This will allow fresh air to flow through
the cockpit.
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Chapter 21-20
Page 25
Figure 13: Smoke removal
A/C Packs Off
Recirc Fans Off
Ebay Fan 3 On
Ram Valve Open
AMS Controller
Outflow Valve
open command
SPDA 1
CPCS Controller
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Chapter 21-20
Page 26
190
21-21 Avionics compartment
Introduction
The avionics compartment ventilation system incorporates forward and middle compartments.
The main function of the forward avionics compartment ventilation system is
to provide a reliable ventilation source that will maintain a safe temperature
in the forward avionics compartment. The forward avionics compartment
ventilation system utilizes three 4.5 in diameter single-speed fans to pull air
from the avionics compartment to the re circulation area.
The fans contain an integral check valve to prevent reverse flow when the
fan is not in use.
The fans are connected in parallel to a common supply duct. An electronic
flow sensor is mounted in the main ventilation supply duct and is used for
system health monitoring.
The main function of the middle avionics compartment ventilation system is
to provide a reliable ventilation source that will maintain a safe temperature
in the middle avionics compartment. The middle avionics compartment ventilation system utilizes two 5.25 in diameter single-speed fans and one 5.25
in diameter, 2-speed fan to pull air from the middle avionics compartment to
the re circulation area.
The fans contain an integral check valve to prevent reverse flow when the
fan is not in use. The fans are connected in parallel to a common distribution
duct. An electronic flow sensor is mounted in the main ventilation duct and
is used for system health monitoring.
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Chapter 21-21
Page 1
Figure 1: Forward electronic bay
EICAS
CMC
FWD EBAY FANS FAIL
EBAY MID FANS FAIL
MAU 1
MAU 2
See 170ICD0156
CGO FWD SOV FAIL
CGO FWD FAN FAIL
Power: DC battery
Power: DC battery
SIGNAL LEGEND
Power: DC battery
ASCB bus
ASCB bus
NIC works to DC ESS
Air flow
1
Forward
SPDA
1
EICC Cooling
Duct
FWD SPDA Signals
MID SPDA Signals
ARINC 429
CAN
2
1 Forward SPDA controls
forward ebay fans
ARINC 429
Pwr: DC ESS 1,DC Bus 2,Gnd SVC
Power: DC ESS 2, Gnd SVC
1
2
3
4
6
1
1
1
Stat
5
Relay On/Off
Relays default powered
on
2
1
2
IO
1
e
I/O
2
RICC
RIGHT AMS
IO
RS422
LEFT AMS
Power: DC ESS
6
RLC
Mid SPDA
oto
rD
riv
Relays default powered
on
Mid SPDA controls mid
ebay fans
1
Pr
oc
es
so
r
3
NC
LICC
M
1
1
e
1
T
I/O
2
oto
rD
riv
T
NC
M
AC ESS Bus
ICC Signals
Power: DC battery
1
EICC
TRU
Pr
oc
es
so
r
Power: DC ESS
2
2
1
1
Forward E-bay
Issue: Aug05
Revision: 00
4
1
Item 59-6
SOV
Item 59-2
Cargo Bay Fan
Power: AC 1
Forward Cargo Bay
Ducted Flow
LICC
RICC
SPDA 2
Item 47D
Fan 2, Two speed
F
3
1
Item 128
Flow Sensor
mounted on
L-ICC duct
1
1
Item 47B
Fan 3
Therm SW
Load Current
Monitoring BIT
28V
3
Therm SW
Item 47A
Item 47A
Item 47A
Fan 3
Fan 1
Fan 2
Ducted Flow
EICC
SPDA 1
Power: Fan 1 = AC 1; Fan 2 = AC 2; Fan 3 = Ess AC
1
High Speed
3
1
Equipment:
See
170ICD0155
Appendix C
28V
Low Speed
3
Therm SW
Therm SW
1
F
1
Therm SW
Item 128
Flow Sensor
mounted on
E-ICC duct
1
Therm SW
3
Therm SW
Equipment:
See
170ICD0155
Appendix B
1
Item 47B
Fan 1
Power: Fan 1 = AC 1; Fan 2 = AC 2;
Fan 3 = Ess AC
Mid E-bay
FOR TRAINING ONLY
Reproduction Prohibited
Cargo Bay
Chapter 21-21
Page 2
190
Forward avionics compartment fan
The forward avionics compartment fan is a 4.5 in diameter single-speed axial flow fan, weighing 4.5 lb with an overall length of 6.5 in,and produces a
volumetric flow rate of 224 ft3/min. The fan wheel is contained in a cylindrical
aluminium housing which incorporates a twin flapper check valve design to
prevent flow in the reverse direction.
The fan is driven by a 3 - phase 115/200 VAC 400 Hz motor. The motor contains an internal thermal protection circuit which is used to shut down the fan
in the event of an over temperature condition. Maintenance of the fan is on
condition.
Forward avionics compartment ventilation ducts
A common supply duct has three fans that are connected in parallel to it. An
electronic flow sensor is mounted in the main ventilation supply duct and is
used for system health monitoring. The ducts are made of composite materials.
Forward avionics compartment flow sensor
The forward avionics compartment flow sensor consists of CRH (Constant
Resistance Heating) element and a platinum RTD (Resistance Temperature
Device) mounted in a stainless steel probe. A constant voltage is applied to
heat the CRH element to a known value. The CRH elements temperature
and electrical resistance will change with variations in mass flow rate. The
RTD element measures the ambient air temperature in the duct. The AMS
(Air Management System) controller uses the CRH element resistance
changes, along with the ambient temperature from the RTD element to calculate a local mass flow rate in the duct. If the local mass flow rate falls below
a certain level (indicating no duct flow) the AMS controller will alert the flight
crew of a low flow condition using the EICAS (Engine Indicating and Crew
Alerting System).
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Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-21
Page 3
Figure 2: Fan failures
MODE
FAN 1
FAN 2
FAN 3
ON
OFF
OFF
FAN 1 FAIL
FAIL
ON
OFF
O
FAN 2 FAIL
ON
FAIL
OFF
O
FAN 1 AND 2 FAIL
FAIL
FAIL
ON
EMERGENCY RAM
ON
ON
OFF
SMOKE REMOVAL
ON
ON
ON
GROUND SERVICE
ON
OFF
OFF
NORMAL
(3) FORWARD ELECTRONICS
BAY FANS
•Same Part Number(P/N 4101634A)
• 4.50 in Diameter
•224 CFM
•Integral check valve
Center electronic bay fans
AC bus
1
ESS bu
3
Recirculation bay
(return air)
AC bus
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Chapter 21-21
Page 4
190
Operation
The forward avionics compartment architecture consists of one flow sensor,
two fans for normal operation and one emergency backup fan.During normal
system operation, the left fan operates and the right and the emergency
backup fan (center) remain in standby mode.If there is a failure of the left fan,
the right fan is commanded on.If there are failures of both left and right fans,
the emergency fan (center) is commanded on.This also turns on, in low
speed mode, the emergency backup fan in the middle avionics compartment.The system utilizes an electronic flow sensor, installed on the ventilation duct, to detect a low flow condition.The low flow sensor switch set point
is adjusted for the flow of one fan in the forward avionics compartment.
Hot Day Ground Operation
For ground operation with the ambient temperature above 86 Deg F (30 Deg
C) both Fan 1 and Fan 2 will be turned on to meet a two fan flow threshold.
Fan 3 will be in standby mode and will be turned on only if Fan 1 or Fan 2
has failed.
The FWD E-BAY FANS FAIL messages shows on the EICAS if:
• the two fans for normal operation (left and right) are failed AND the aircraft is on ground, OR;
• The emergency backup fan is failed AND the aircraft is on ground, OR;
• The flow sensor is failed AND the aircraft is on ground,OR;
• The flow sensor indicates that there is NOT at least one fan operating
(low-flow sensor reading),OR;
• All three fans are failed AND the aircraft is in flight.
A single fan failure results in only one CMC (Central Maintenance Computer) message.It is important to note that the forward avionics compartment
ventilation system can maintain adequate compartment cooling with one fan
operational.
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Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-21
Page 5
Figure 3: Forward electronic fan operation
FLOW
THESHOL
D
An electronic flow sensing device is also used to verify
that there is adequate airflow in the ventilation duct.
ALTITUD
E
<
Low Flow Sensor Reading Below 1 Fan Limit Valid
Flow Sensor Failed
WOW
Switch
FWD E-Bay Fan 1 Failed
OR
AND
AND
FWD E-Bay Fan 2 Failed
(60 second Delay)
FWD E-Bay Fan 3 (Backup) Failed
OR
FWD E-BAY
FAN FAIL
FWD E-Bay Fan 1 Overtemp
FWD E-Bay Fan 2 Overtemp
FWD E-Bay Fan 3 Overtemp
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
AND
Ventilation fans in the forward
and mid electronics bay are
continuously monitored by the
AMS controller using load
current monitoring.
Chapter 21-21
Page 6
190
The middle avionics bay fans
tion circuit which is used to shut down the fan in the event of an over temperature condition. Maintenance of the fan is on condition.
The centre avionics bay ventilation system contains fans that pull air from
the passenger cabin under floor areas through the centre avionics compartment, and exhaust the air into the re circulation bay.
Middle avionics compartment flow sensor
The two single-speed fans and one two-speed fan are connected in parallel
to a common distribution duct, and contain integral check valves in order to
prevent reverse flow. A sensor mounted in the fan supply duct provides system health monitoring.
Middle avionics compartment fan
The middle avionics compartment fan is a 5.25 in diameter single-speed axial flow fan, weighing 6.1 lb with an overall length of 7.25 in, and produces a
volumetric flow rate of 547 ft3 /min. The fan wheel is contained in a cylindrical aluminium housing which incorporates a twin flapper check valve design
to prevent flow in the reverse direction.
The fan is driven by a 3-phase 115/200 VAC 400 Hz motor. The motor contains an internal thermal protection circuit which is used to shut down the fan
in the event of an over temperature condition. Maintenance of the fan is on
condition.
The middle avionics compartment flow sensor consists of a CRH element
and a platinum RTD element collocated in a stainless steel probe. A constant voltage is applied to heat the CRH element to a known value. The CRH
elements temperature and electrical resistance will change with variations in
mass flow rate. The RTD element measures the ambient air temperature in
the duct. The AMS controller uses the CRH element resistance changes,
along with the ambient temperature from the RTD element to calculate a local mass flow rate in the duct. If the local mass flow rate falls below a certain
level (indicating no duct flow) the AMS controller will alert the flight crew of
a low flow condition using the EICAS
Middle avionics compartment fan (2-speed)
The 2-speed middle avionics compartment fan is a 5.25 in diameter axial
flow fan, weighing 6.7 lb with an overall length of 7.25 in, and produces a
volumetric flow rate of 370 ft3/min. under low speed operation and 547 ft3/
min. in the high speed mode of operation. The fan wheel is contained in a
cylindrical aluminium housing which incorporates a twin flapper check valve
design to prevent flow in the reverse direction. The fan is driven by a 3-phase
115/200 VAC 400 Hz motor. The motor contains an internal thermal protec
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FOR TRAINING ONLY
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Chapter 21-21
Page 7
Figure 4: Fan failures
MID ELECTRONICS BAY FANS
MO DE
FAN 1
FAN 2
ON
OFF
O
FAN 1 FAIL
FAIL
ON
OFF
FAN 2 FAIL
ON
FAIL
OFF
O
FAIL
FAIL
ON
O
EMERGENCY RAM
ON
ON
SMOKE REMOVAL
ON
ON
OFF
ON
GROUND SERVICE
ON
OFF
OFF
NORMAL
FAN 1 AND 2 FAIL
Issue: Aug05
Revision: 00
FAN 3
OFF
• (2) Single speed fans(P/N 410724A (2 SPD)
•5.25 Diameter
•547 CFM
•Integral check valve
•(1) Two speed fan (P/N 410638A)
•5.25 Diameter
•547, 370 CFM
•Integral check valve
FOR TRAINING ONLY
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Chapter 21-21
Page 8
190
Middle Avionics Compartment Fan Operation
The central electronics bay ventilation system consists of one flow sensor,
two single speed fans for normal operation and one two speed emergency
backup fan.
The central electronics bay fans are controlled by the Secondary Power Distribution Assembly.
During normal system operation Fan 1 operates normally with Fan 2 and
Fan 3 in standby mode.
If there is a failure of Fan 1, Fan 2 will be automatically turned on.
If both Fan 1 and Fan 2 have failed, Fan 3 will be commanded on high
speed.
The low speed on the two speed fan is used during Ram Air Turbine
deployment to minimize power consumption.
Fan number 3 will be turned on low speed by default any time the
backup fan in the forward E-Bay is activated.
A single fan failure will result in only one CMC message.It is important to
note that the middle avionics compartment ventilation system can maintain
adequate compartment cooling with one fan operational.
NOTE: When the RAT is deployed, the middle avionics compartment emergency fan uses the low speed setting to minimize power consumption.
Hot Day Ground Operation
For ground operation with the ambient temperature above 86 Deg F
(30 Deg C) both Fan 1 and Fan 2 will be turned on to meet a two fan flow
threshold.
Fan 3 will be iln standby mode and will be turned on (high speed) only
if Fan 1 or Fan 2 has failed.
The CENTER E-BAY FANS FAIL message shows on the EICAS if:
• The two fans for normal operation (left and center) are failed AND the aircraft is on ground, OR;
• The emergency backup fan (right) is failed AND the aircraft is on ground,
OR;
• The flow sensor is failed AND the aircraft is on ground, OR;
• The flow sensor indicates that there is NOT at least one fan operating
(low-flow sensor reading), OR;
• All three fans are failed, the aircraft is in flight AND the RAT (Ram Air Turbine) is not deployed.
Issue: Aug05
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Chapter 21-21
Page 9
Figure 5: Centre electronic bay
FLOW
THRESHOLD
An electronic flow-sensing device is also used to verify that
there is adequate airflow in the ventilation duct.
ALTITUD
E
<
Low Flow Sensor Reading
Flow Sensor Failed
WOW
Switch
Mid E-Bay Fan 1 Failed
OR
AND
Mid E-Bay Fan 2 Failed
AND
Mid E-Bay Fan 3
(Back-up) Failed
(60 second Delay)
Ventilation fans in the forward and mid
electronics bay are continuously monitored by
the AMS controller using load current monitoring.
WOW
Switch
RAT Deployed
Switch
Issue: Aug05
Revision: 00
NOT
OR
CENTER EBAY FAN
FAIL
AND
NOT
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-21
Page 10
190
21-27 Forward cargo compartment
Introduction
The forward cargo compartment ventilation system draws air from the cabin
underfloor area by means of a single fan, and exhaust the air through the
cargo compartment shut-off valve into the re circulation bay area to the outflow valve.
During normal operation the fan is operating, and the shut-off valve is open
and monitored by the AMS controller. In case of fire, the fan is turned off and
the valve is immediately closed.
A check valve ensures that there is no airflow toward the passenger compartment.
Note: This cargo compartment ventilation system is optional.
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Chapter 21-27
Page 1
Figure 1: Forward cargo compartment
Fan
Cabin air
Animal Cargo Bay
Shut off valve
Outflow valve
AMS
Note:
This cargo compartment ventilation system is optional.
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Chapter 21-27
Page 2
190
Forward cargo compartment fan
The forward cargo compartment fan is a 4.5 in diameter single-speed axial
flow fan. The fan is driven by a 3-phase 115/200 VAC 400 Hz motor. The
motor contains an internal thermal protection circuit which is used to shut
down the fan in the event of an over temperature condition. The fan wheel
is contained in a cylindrical aluminium housing.
Forward cargo compartment check valve
The forward cargo compartment check valve is a 3.5 in diameter dual-flapper check valve. The valve is mounted downstream of the forward cargo
ventilation fan in the forward cargo compartment supply duct.
Forward cargo compartment shut off valve
The forward cargo compartment shut off valve is a 3.5 in diameter pneumatic actuated valve. The valve is mounted in the forward cargo ventilation system outlet duct and utilizes a 28 VDC (Volt Direct Current) solenoid for open/
close function.
Forward cargo compartment ventilation ducts
Air is distributed to the forward cargo compartment by underfloor ducts, on
the LH side of the cargo compartment (upstream and downstream of the fan)
and one in the right aft bulkhead of the cargo compartment.
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FOR TRAINING ONLY
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Chapter 21-27
Page 3
Figure 2: Fwd cargo compartment
Outlet Shutoff Valve
((Pneumatically
Actuated))
Air Entrances
Bleed/Fairing Duct
Inlet Fan
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Chapter 21-27
Page 4
190
Indications
If the forward cargo fan fails, the EICAS message CARGO FWD FAN FAILS
will illuminate, or if the shut-off valve fails, the EICAS message CARGO
SHUT-OFF VLV FAIL will be displayed, either on ground or in the air.
Valve position failures are indicated on the CMC.
On the MFD Environmental Control System synoptic page the fan operation,
valve position and the cargo compartment temperature are displayed.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
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Chapter 21-27
Page 5
Figure 3: Indications
Load current monitoring is used to monitor ventilation fan
operation.
Forw ard Cargo Bay Fan
Failed ON
(60 second Delay)
CGO FWD FAN FAIL
AND
Forward Cargo
Bay Fire
OR
AND
Forw ard Cargo Bay Valve
Failed OPEN
CGO FWD V ENT FAIL
CGO FWD SOV FAIL
(60 second Delay)
MAU Logic
The Forward Cargo Shutoff Valve is tested each time the AMS controller is
powered up. The AMS controller commands the valve full open and then
closed. This valve has position switch feedback for position indication.
EICAS message CGO FWD VENT FAIL will be displayed if the valve has
failed in the open position.
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Chapter 21-27
Page 6
190
ECS Built-in Test
E-Bay fans in the forward and mid E-Bays are continuously monitored by the
AMS controller using load current monitoring and overheat detection. E-Bay
flow sensors are also used to verify that there is adequate airflow in the EBay ventilation duct. In addition, the E-Bay fans in the forward and mid EBays are checked for proper operation each time the AMS controller is powered up, and two minutes after each aircraft landing. This BIT is automatically initiated by the AMS controller to ensure that each fan is operational and
is capable of providing adequate airflow. This test will detect fan failures that
are not detected by continuous load current monitoring. During this power
up/ post landing fan operational test the AMS controller commands only one
E-Bay fan on in each E-Bay and uses the E-Bay flow sensor to verify that
the fan is operating. This test is performed on each fan. If all the fans in a
common electronics bay (forward or mid) do not meet the minimum flow requirements of this test, the AMS controller will determine that the E-Bay flow
sensor in the associated bay has failed.
The forward cargo compartment shutoff valve is tested each time the AMS
controller is powered up. The AMS controller commands the valve full OPEN
and then CLOSED. This valve has position switch feedback for position indication. EICAS message CRG FWD VENT FAIL will be displayed if the
valve has failed in the OPEN position.
The recirculation bay smoke detector is tested by the AMS controller using
the recirculation bay smoke detectors automated BIT function. The BIT is
performed whenever the AMS controller is powered up (after shut down) and
two minutes after each aircraft landing. The AMS controller sends a test signal to the recirculation bay smoke detector that causes the recirculation bay
smoke detector to perform an internal BIT: The recirculation bay smoke detector BIT sequence includes fan current monitoring and a test of the smoke
detecting and alarm capability. If the recirculation bay smoke detector does
not pass the BIT sequence the AMS controller will generate the EICAS message RECIRC SMK DET FAIL to alert the flight crew that the recirculation
bay smoke detector is inoperative. In addition, continuous BIT monitors sets
the RECIRC SMK DET FAIL EICAS Message if the recirculation bay smoke
detector has been failed due to an electrical power supply lost (open circuit)
or Smoke Detected signal is not valid for 10 or more seconds.
The emergency ram air ventilation valve is tested each time the AMS controller is powered up. The AMS controller commands the valve full OPEN
and then CLOSED. This valve has position switch feedback for position indication. EICAS message RAM AIR FAULT will be displayed if the valve has
failed in the CLOSED position.
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FOR TRAINING ONLY
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Chapter 21-27
Page 7
Figure 4: ECS Built in test
MIDDLE AVIONICS COMPARTMENT
FWD AVIONICS COMPT
DC GND SVC BUS
J7
DC BUS 2
J3
PRESS 10R
ANALOG 2R
J22
PRESS 10L
ANALOG 2L
J21
PRESS 9R
ANALOG 1R
J24
ANALOG 1L
J19
PRESS 9L
DC GND SVC BUS
FAN
AVIONICS COMPARTMENT FLOW SENSOR
(SDS 21-26)
(MPP 21-26-02)
C
GROUND
TEMPERATURE
MASS FLOW
TEMPERATURE
MASS FLOW
+28 VDC
FLOW
SENSOR
C
GROUND
VENTILATION
DUCTS
+28 VDC
28VDC
28VDC
J3
B
SPDA 2
(SSM 24-61-80)
J2
A
DC BUS 1
SPDA 1
(SSM 24-61-80)
AVIONICS COMPARTMENT FLOW SENSOR
(SDS 21-26)
(MPP 21-26-05)
D
MIDDLE AVIONICS COMPARTMENT
FORWARD AVIONICS COMPARTMENT
VENTILATION
DUCTS
A
VENTILATION
DUCTS
VENTILATION
DUCTS
FAN
FLOW
SENSOR
VENTILATION
DUCTS
Issue: Aug05
Revision: 00
B
D
FOR TRAINING ONLY
Reproduction Prohibited
FORWARD AVIONICS
COMPARTMENT FLOW SENSOR
MIDDLE AVIONICS
COMPARTMENT FLOW SENSOR
C
D
Chapter 21-27
Page 8
190
21-28 Electronic Rack Ventilation System
Introduction
The electronic-equipment-rack ventilation system provides airflow for cooling of nonessential electronic equipment installed in a dedicated equipment
rack.In the event of smoke resulting from failure of electronic equipment, the
rack ventilation system provides a mean to discharge the smoke overboard.
The electronic-equipment-rack is installed in the lower compartment, behind
the aft partition of the aft cargo compartment.
The shelves of the rack contain the several units required for the proper
functioning of the in-flight entertainment system.Some of these units require
forced ventilation, supplied by a dedicated and independent ventilation system, in order to minimize effects on air-conditioning distribution, pressurization and smoke management.
The rack ventilation system comprises:
•
•
•
•
•
•
•
One electric-motor-driven fan
An overboard air-discharge port
Two electric-motor-driven air shutoff valves
One smoke detector
One airflow switch
Three airflow-limiting venturis
Associated air collection and conveyance ducts
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Chapter 21-28
Page 1
Figure 1: System layout
ZONE
250
OVERBOARD
DISCHARGE
A
VENT SHUTOFF
VALVE
VENTILATION
DUCTS
GROUND SHUTOFF
VALVE
FAN
SMOKE
DETECTOR
A
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Chapter 21-28
Page 2
190
System description
Plenums and ducts collect air from the rack and discharge it overboard
forced by a fan (on-ground) or by cabin differential pressure through a venturi (in-flight).
The discharge duct system splits into three branches and later joins together
to form a common exhaust duct.The branches are called: ground line, vent
line and bypass line.The ground line has an electric-motor-driven air shutoff
valve.The ground valve is always open on ground when the fan is ON.It closes in flight to prevent excessive flow leakage.The vent line is the main path
for the ventilation flow in flight.It contains an electric-motor-driven air shutoff
valve and a flow limiting venturi.The vent valve is always open, except under
certain conditions when evacuation of smoke generated in other aircraft regions could be affected.The bypass line is always open to ensure a minimum amount of cooling flow, whenever the vent valve is closed.It contains
a flow-limiting device to prevent excessive flow leakage that could jeopardize the smoke containment in other areas of the airplane.An additional venturi is installed in the common exhaust duct, downstream of the valves.Its
purpose is to minimize the impact on the cabin pressurization control system.The venturi is sized to ensure that cabin pressure remains below the “HI
CABIN” indication set point, even in single-pack mode with the ground valve
failed open.
A smoke detector is installed in the rack ventilation duct.In the event of
smoke resulting from failure of electronic equipment, the smoke detector
generates an EICAS (Engine Indicating and Crew Alerting System) message for the crew, and automatically shuts down the electronic equipment
rack.The pilot is also required to manually shut off the rack as an added precaution.
There is also an airflow switch used to detect loss of cooling flow.
Exhaust air or smoke is captured from the upper part of the rack and discharged overboard through a dedicated fuselage port located at the RH
(Right-Hand) side, aft part of the aircraft fuselage, opposite to the vacuum
and waste fuselage port.The cooling air is enclosed and does not enter the
cargo compartment.It is totally exhausted overboard on the ground and in
flight.
Issue: Aug05
Revision: 00
Control function, fault indication, and testing of the electronic-equipmentrack ventilation system operation is accomplished by dedicated electrical
circuits that are independent of other aircraft control circuits.
Airflow Switch
The airflow switch is a flow-sensing unit that uses thermal dispersion technology where two platinum RTD (Resistance Temperature Detector) are located in the airflow element.It is a solid state unit powered by 28 VDC (Volt
Direct Current).
The airflow switch is installed in the rack exhaust-air discharge-line (upstream the smoke detector) and has the function of protecting the electronic
equipment from an overheat condition due to lack of air cooling.It is only deactivated (without shutting down the system) during an aircraft single pack
operation.At this time, both shutoff valves are closed and the minimum required airflow to cool the rack is obtained through the bypass line.
Fan
The function of the fan (brushless type) is to provide ventilation to the electronic equipment rack when the aircraft is on the ground.The fan draws air
from the rack and discharges it overboard through the ground and vent shutoff valves.
The ventilation fan is of the 4.5 in diameter, single speed and axial flow
type.It is driven by a 3-phase 115/200 VAC/ 400 Hz motor.The motor contains an internal thermal protection circuit which is used to shut down the fan
in the event of an overtemperature condition.The fan wheel is installed in a
cylindrical aluminium housing.
The fan is attached to a structure support and stays on aircraft during the
rack removal.A rubber flexible sleeve makes the connection to the exhaust
duct of the rack and absorbs excessive vibration.
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-28
Page 3
Figure 2: Components view
B
ZONE
250
A
FAN
A
AIRFLOW
DIRECTION
SMOKE
DETECTOR
AIRFLOW
SWITCH
B
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Chapter 21-28
Page 4
190
Ventilation ducts
The air/smoke extracted from the electronic equipment rack passes the fan
and reaches the shutoff valves through a set of 4.5 in diameter aluminium
ducts.Then the air/smoke is directed to the atmosphere through a vent duct
and a fuselage port located at the right hand side of the fuselage, behind the
aft avionics compartment.
The 3 in diameter vent duct is also made of aluminium and runs from the
shutoff valves to a 2.5 in diameter vent port at the right side of the fuselage
skin.The vent duct has an upward loop to avoid de-icing fluids ingestion and
water ingression during ditching.A venturi in the overboard exhaust duct prevents excess loss of cabin pressure in case of a duct failure.
A duct bypasses the ground shutoff valve and prevents excessive loss of
cabin pressure in case of duct failure.It also keeps a minimum required airflow for the rack cooling when the vent shutoff valve is closed due to smoke
detection in the air conditioning system (basically in the recirculation bay),
single pack operation or for dispatch ability when one pack is inoperative.
Shutoff valves
The ground and vent shutoff valves are identical.They are attached to the aft
floor panel (aft avionics compartment) close to the aft pressure bulkhead.
These valves are of the electric-motor-driven butterfly type and consists of
two major subassemblies: an actuator and a butterfly valve.The actuator assembly controls the position of the valve.It comprises of an electric motor, a
gear train, position control/indication switches, an electrical connector, and
a housing.The actuator moves the valve to each of the two desired discrete
positions, fully closed and fully open, based on command from the aircraft.The motor is a precision, aircraft-quality, brush-type 28 VDC permanent magnet.
The valves contain limit switches that control the motor and provide valve
position indication.
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FOR TRAINING ONLY
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Chapter 21-28
Page 5
Figure 3: Components view
ZONE
250
A
OVERBOARD
DISCHARGE
VENTILATION
DUCTS
AIRFLOW
DIRECTION
B
A
GROUND SHUTOFF
VALVE
B
VENT SHUTOFF
VALVE
Issue: Aug05
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GROUND/VENT
SHUTOFF VALVE
(SAME PART NUMBER)
C
C
REDUCED
FLOW DUCT
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-28
Page 6
190
Maintenance Test Panel
The maintenance test panel is installed in the aft electronics-compartment
rack on the right-hand side at the upper shelf.It provides a mean for testing
the smoke detector and also to verify the operation of the shutoff valves
(ground/vent).The panel also indicates failures of the smoke detector, vent
shutoff valve, ground shutoff valve and rack cooling system (fan and airflow
switch) through 4 LED (Light-Emetting Diode)s (amber color).These failure
indications are latched in order to enable the maintenance crew to evaluate
the problem on the ground.
Monitoring Panel (LEDS)
The ventilation system monitoring panel consists of 4 LEDs installed near
the G2 Galley, on the side panel, forward of the LH passenger entry-door:
•
•
•
•
COOLING FAIL
SMOKE DETECTOR FAIL
GROUND VALVE FAIL
VENT VALVE FAIL
Just like the maintenance test panel, these LEDs also indicate eventual failures of the rack ventilation system LRU (Line Replaceable Unit)s.The main
difference is that the monitoring panel has an easier access and is much
simpler (it does not have test functions, for instance).The monitoring panel
is used for maintenance purposes only (such as troubleshooting).
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Chapter 21-28
Page 7
Figure 4: Maintenance Test Panel
ZONE
252
B
A
IFE VENT/SMK DET
VENT VALVE
CLOSE
OPEN
CLOSE
FAIL
CLOSE
GROUND VALVE
SMK DET
TEST
PASS
VENT/SMK DET
DC POWER
COOL
FAIL
FAIL
AMBER LEDS
RESET
TEST
5
A
MAINTENANCE/TEST PANEL
B
MAINTENANCE/TEST PANEL
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Chapter 21-28
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190
Operation
During ground operation, the fan draws the air from the underflow compartment through the rack equipment and exhausts it to the outside.The ground
valve and vent valve are open.The airflow switch monitors the airflow rate to
ensure adequate cooling capacity for the electronic units.
During takeoff, when the TLA (Thrust Lever Angle) is moved above 60 degrees and the parking brake is released, the ventilation system is automatically configured to the flight mode.During descent and landing, this
configuration will remain until 20 s after touchdown, when the system reverts
back to ground mode.
In the flight mode, the ground valve is closed and the fan is shut off.The vent
valve and the bypass line are open.The pressure difference between the
cabin and the outside air serves as the driver for cabin air to flow through the
rack ventilation system discharging the exhaust air to the outside.The airflow
switch monitors the airflow rate to ensure adequate cooling capacity for the
electronic units.Its signal is inhibited during flight under 17500 ft +/- 500 ft,
when the ventilation system has not reached its nominal capability.
Fan Operation
During normal ground operation, the fan is commanded ON and both shutoff
valves are commanded OPEN.After takeoff or in response to a smoke detection on ground, the fan is commanded OFF and the ground shutoff valve
is commanded CLOSED.
The fan operates on the ground even when only the ground service power
bus is available, in order to ventilate the Wireless Aircraft Unit (WAU).
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Chapter 21-28
Page 9
Figure 4: Operation
OVERBOARD
DISCHARGE
FLOW LIMITING
NOZZLE
ELECTRONIC RACK
EQUIPMENT
VENT SHUTOFF
VALVE
SMOKE
DETECTOR
MRM
MRM
WAU
VSU
XM RADIO
FLOW LIMITING
NOZZLE
AIRCRAFT SKIN
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GROUND SHUTOFF
VALVE
COOLING
FAN
VENTILATION
DUCTS
FOR TRAINING ONLY
Reproduction Prohibited
RDA
AIRFLOW
SWITCH
MRM
VMU
Chapter 21-28
Page 10
190
Ground Shutoff Valve Operation
Vent Shutoff Valve Operation
When the aircraft is on the ground, the normal rack ventilation system operation uses the ambient air from the under-floor compartment.A dedicated
electric fan draws this ambient air through the rack equipments and discharge it overboard through the ground shutoff valve.
The vent shutoff valve is normally in the OPEN position.In flight conditions,
the cabin differential pressure draws air from the rack and discharge it overboard through the vent shutoff valve and the fuselage port.
The ground shutoff valve is commanded to the open position after the following conditions have been achieved:
•
•
•
•
The vent shutoff valve is commanded to the closed position after the following conditions have been achieved:
• single pack operation
• smoke detected in the recirculation bay
TLA < 60°
Time delay after WOW (Weight-on-Wheels) - 20s
Parking brake switch - ON
Rack power - ON
Air Flow Switch Operation
At the same time, the ground shutoff valve is commanded OPEN, the fan is
commanded ON.
The ground shutoff valve is commanded to the closed position after the following conditions have been achieved:
• TLA > 60°
• Parking brake switch - OFF
The airflow switch is a unit installed in the rack exhaust line, upstream of the
smoke detector.The function of the airflow switch is to protect the rack equipments from an overheat due to a lack of air cooling.
Upon detection, the signal from the switch is sent via relays to the SPDA,
which then automatically removes the electrical power to the rack to protect
the LRUs.The airflow switch signal is inhibited during flight under 17500 ft +/
- 500ft, when the ventilation system has not reached its nominal capability.
At this time, the electrical power is removed from the fan.
A bypass line around the ground shutoff valve allows a minimum airflow required for the rack equipment cooling when the aircraft is dispatched with
single pack operation and the vent shutoff valve is in the closed position.
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Chapter 21-28
Page 11
Figure 5: Operation
OVERBOARD
DISCHARGE
FLOW LIMITING
NOZZLE
ELECTRONIC RACK
EQUIPMENT
VENT SHUTOFF
VALVE
SMOKE
DETECTOR
MRM
MRM
WAU
VSU
XM RADIO
FLOW LIMITING
NOZZLE
AIRCRAFT SKIN
GROUND SHUTOFF
VALVE
COOLING
FAN
RDA
AIRFLOW
SWITCH
VENTILATION
DUCTS
MRM
VMU
TABLE - ELETRONIC-EQUIPMENT-RACK VENTILATION SYSTEM - SYSTEM SCHEMATIC
SYSTEM OPERATION CONDITION
AIRCRAFT OPERATION CONDITION
On the ground, EXCEPT takeoff (TLA > 60É and parking
brake released); and during landing (until 20 s after WOW)
System normal operation
In flight, INCLUDING takeoff (TLA > 60Éand parking
brake released) and landing (until 20 s after WOW)
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LOGIC DESCRIPTION
·
·
·
Fan commanded to ON
·
·
·
Fan commanded to OFF
Ground valve commanded to OPEN
Vent valve remains OPEN
Ground valve commanded to CLOSE
Vent valve remains OPEN
Chapter 21-28
Page 12
190
Maintenance Test Panel Operation
The single 3-position momentary toggle switch (with normal central position
lever-lock) provides a mean for operationally checking the vent shutoff valve
and the ground shutoff valve.When the aircraft is on the ground, in normal
operation condition, both SOV (Shutoff Valve)s must be in the OPEN position, confirmed by the LED “OPEN” indication illuminated in green color.
The operational checks are achieved by lifting the toggle switch and moving
it UP (to test the vent valve) and DOWN (to test the ground valve).At this
time the LED “OPEN” indication will turn OFF and after a few seconds (5-8
s) the LED “CLOSED” indication will turn ON indicating full traveling of the
applicable shutoff valve.When you release the toggle switch and locks it in
the central position, that will open the applicable shutoff valve and the LED
“CLOSED” indication will turn OFF.Consequently, the LED “OPEN” indication will turn ON.
The circuit breaker is installed to permit maintenance on the applicable LRU
powered by 28 VDC such as: smoke detector, airflow switch, SOVs, relays
and LEDs.
The LED RESET 2-position momentary toggle switch (with normal position
lever-lock) allows the LED “FAIL” indication (amber color) to be cleared after
the cause of the fault indication has been fixed.
The LED TEST 2-position momentary toggle switch (with normal position lever-lock), when activated, will send a ground and indicate that all LEDs (amber) are operational.The other five LEDs (green) can be tested during the
ground and vent valve operational checks and the smoke detector test.
The smoke detector test switch allows complete testing of the smoke detection and indication system for the electronic equipment rack.When the test
switch is momentarily pressed, it illuminates in white color indicating that the
test has initiated.When the test is successfully completed, the LED “PASS”
indication will illuminate in green color and the “IFE RACK SMOKE” caution
message is displayed on the EICAS.At the same time, an aural warning activated in the cockpit.
When the test switch is held pressed longer than 10 s, the auto shutdown
function is checked.In this case, the power is removed from rack components and the IFE RACK SMOKE message is displayed on EICAS.At the
same time, an aural warning is activated in the cockpit.
There are four failure LEDs (amber color) on the maintenance test panel:
vent valve, ground valve, smoke detector (auto test) and rack cooling system (ducting, fan or airflow switch).They are intended to help the ground
crew to determine which LRU needs troubleshooting.These failure indications are latched once they occur.
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Page 13
Figure 7: Maintenance Test Panel Operation
SYSTEM OPERATION CONDITION
AIRCRAFT OPERATION CONDITION
On the ground: ground valve failed closed
·
Maintenance Test Panel indicates ground valve failed
·
·
·
IFE (In Flight Entertainment) power commanded to OFF
·
·
IFE power commanded to OFF
In flight (including takeoff and landing): ground valve
failed open
·
·
IFE power remains ON
Maintenance Test Panel indicates ground valve failed
Any flight condition: vent valve failed closed
·
Maintenance Test Panel indicates vent valve failed
·
·
IFE power commanded to OFF
·
·
·
·
·
IFE power commanded to OFF
·
·
·
·
·
IFE power commanded to OFF
·
·
·
·
IFE power remains ON
Fan remains OFF
On the ground: loss of cooling
In flight: loss of cooling
IFE VENT/SMK DET
VENT VALVE
CLOSE
OPEN
CLOSE
FAIL
CLOSE
System abnormal operation
GROUND VALVE
SMK DET
TEST
PASS
VENT/SMK DET
DC POWER
In flight: smoke detector failure
COOL
FAIL
FAIL
In flight: smoke detected in the rack
AMBER LEDS
RESET
TEST
5
On the ground: smoke detected in the rack
MAINTENANCE/TEST PANEL
In flight and:
Aircraft abnormal operation
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Revision: 00
LOGIC DESCRIPTION
·
·
Single pack operation and;
Recirculation-bay smoke detector failed or; smoke in
the avionics compartments
FOR TRAINING ONLY
Reproduction Prohibited
Fan commanded to OFF
Maintenance Test Panel indicates cooling failure
Maintenance Test Panel indicates cooling failure
Maintenance Test Panel indicates cooling and smoke detector failure
Fan remains OFF
Ground valve remains CLOSED
Vent valve remains OPEN
EICAS message ²IFE RACK SMOKE² and aural message
Fan remains ON
Ground valve remains OPEN
Vent valve remains OPEN
EICAS message ²IFE RACK SMOKE² and aural message
Ground valve remains CLOSED
Vent valve commanded to CLOSED
Chapter 21-28
Page 14
190
21-30 Pressurization
Introduction
The Cabin Pressure Control System is designed for completely automatic
operation. The pressurization controller has two fully independent channels,
which alternate after each flight (70 seconds after touchdown). Both channels provide a manual back up function. The system utilizes digital electronics to communicate with the other aircraft systems via ARINC 429 buses and
discrete signals.
The Cabin Pressure Control System, in automatic mode, will control the
pressurization in the cabin to a maximum cabin altitude of 8,000ft. The system will also control the maximum differential pressure of 8.4psi up to
41,000ft aircraft altitude with a comfortable rate of change in climb and descent modes. These limits are achieved by modulating the airflow through
the outflow valve. Separate mechanical positive and negative relief valves
satisfy the safety relief functions.
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Chapter 21-30
Page 1
Figure 1: The Cabin Pressure Control System
MAU 3
MAU 2
Safety
Valve
Static Port
Heater
MAU 1
Neg
Relief
Valve
Channel 1
Auto/
Manual
SPDA
Forward SPDA
RS422
Channel 2
Auto/
Manual
LEFT AMS RIGHT AMS
OFV
CPCS Controller
PRESSURIZATION
OUTFLOW
O2
Altitude
Switch
MODE
STOP
DOWN
AUTO
UP
DUMP
DOWN
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LFE
CTRL
MAN
STOP
UP
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Page 2
190
The cabin pressure control system
The Cabin Pressure Control System includes the following components:
•
•
•
•
The pressurization controller,
the cabin outflow valve,
the negative pressure relief valve and
safety valve.
The flight deck interface contains the pressurization control panel, including
an auto and manual selector rotary switch, the EICAS display with Cabin
Pressure Control System related messages, and the EICAS display lower
section where cabin altitude, rate of change, maximum differential pressure
and landing field elevation are displayed.
The system also includes the multi-function display, for viewing CMC messages, and the Multi function Display ECS synoptic page to monitor the outflow valve position.
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Chapter 21-30
Page 3
Figure 2: The cabin pressure control system components
ARINC
INPUTS
PRESSURE
SCHEDULES
PRESSURE
SCHEDULES
SELECTOR
RATE
SCHEDULES
RATE
SCHEDULES
SELECTOR
MODE
LOGIC
RATER
LIMITER
P REF
LIMITER
MAXIMUN
DELTA-P
LIMITER
SPEED
PRESSURE
SERVO
COMMAND
CABIN
PRESSURE
MOTOR
INTERFACE
DC MOTOR 1
BITE
INDICATION
POTENTIOMETER 1
CPCS CONTROLLER
CHANNEL 1
(SDS 21-31)
(MPP 21-31-01)
(WM 21-31-50)
DISCRETE
INPUTS
OUTFLOW
VALVE
(SDS 21-31)
(MPP 21-31-02)
(WM 21-31-50)
ARINC
INPUTS
PRESSURE
SCHEDULES
MODE
LOGIC
RATE
SCHEDULES
PRESSURE
SCHEDULES
SELECTOR
RATER
LIMITER
RATE
SCHEDULES
SELECTOR
P REF
LIMITER
MAXIMUN
DELTA-P
LIMITER
SPEED
PRESSURE
SERVO
COMMAND
CABIN
PRESSURE
MOTOR
INTERFACE
DC MOTOR 2
BITE
INDICATION
POTENTIOMETER 2
CPCS CONTROLLER
CHANNEL 2
(SDS 21-31)
(MPP 21-31-01)
(WM 21-31-50)
DISCRETE
INPUTS
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190
The pressurization control panel
The PRESSURIZATION control panel is installed on the right hand side of
the overhead panel in the cockpit. It has these switches:
• A rotary MODE selector switch
• A rotary spring-loaded LFE (Landing Field Elevation) switch
• A rotary spring-loaded CABIN ALT switch
• A guarded DUMP push-button switch
The LFE switch is spring-loaded to the STOP position. When it is turned to
the UP position, the LFE is increased. When it is turned to the DOWN position, the LFE is decreased. The LFE increases by 50 ft every 0.5 s.
After 2 s, the LFE increases by 500 ft every 0.5 s.
The DUMP switch is used to depressurize the cabin in the event of emergency evacuation, smoke evacuation or to rapidly equalize differential pressure. The cabin is depressurized at a rate of 2000 SL ft/min. up to 12400 ft
+/- 50 ft cabin altitude.
The MODE selector switch has three position:
• AUTO for automatic operation
• LFE CTRL for manual selection of LFE
• MAN for manual operation
When the MODE switch is set to AUTO, the CPCS operates fully automatically without any crew attention during flight. The CPCS takes the LFE value
from the FMS.
When the MODE switch is set to LFE CTRL, the CPCS is still in automatic
operation, but the LFE values are selected manually via the LFE switch. The
LFE CTRL is used together with the LFE switch to select LFE. The LFE ranges from -2000 ft to 14000 ft.
When the MODE switch is set to MAN, the CPCS operates in manual mode.
The MAN switch is used together with the CABIN ALT switch to manually
control the position of outflow valve.
The CABIN ALT switch controls the position of the outflow valve in the manual mode of operation. It only functions when the MODE selector switch is
set to MAN. It has these positions:
• UP
• DOWN
• STOP
The OUTFLOW switch is spring-loaded to the STOP position. When it is
turned to the UP position, the outflow valve is driven to the open position.
When it is turned to the DOWN position, the outflow valve is driven to the
closed position. The outflow valve is driven at a rate of 2 degrees per second.
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Chapter 21-30
Page 5
Figure 3: The pressurization control panel
PRESSURIZATION
A/C Packs Off
Recirc Fans Off
Ebay Fan 3 On
Ram Valve Open
OUTFLOW
STOP
CLOSE
AUTO
OPEN
LFE
CTRL
MAN
DUMP
LFE
-
+
AMS Controller
Outflow Valve
Command
Forward SPDA
CPCS Controller
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190
The cabin pressurization controller
Positive Differential Pressure Limitation
The CPCS controller provides automatic cabin pressure control, failure
monitoring and recording and communication with other aircraft systems.
The CPCS controller has two separate, but identical, fully independent control channels. Each control channel includes:
• Two cabin pressure sensors
• Cabin pressure control circuit
• BITE (Built-in Test Equipment) control circuit
• Motor driver circuit
• ARINC (Aeronautical Radio Incorporated) 429 I/O Interface
• Discrete I/O interface
• Serial Interface for software down load and shop interrogation purposes
• EMI (ElectroMagnetic Interference) protection circuits on separate
board
• Non-volatile fault and flight data storage
The control channels communicate with each other via internal communication buses. Each control channel is supplied by two separate aircraft power
supply sources for redundancy.
In automatic mode, only one control channel controls the outflow valve at
any time, the other is in hot stand-by. The CPCS controller switches active
control from one control channel to the other after each flight or when an
auto failure occurs. This gives the CPCS a dual redundant architecture.
The manual mode of operation overrides and bypasses the CPCS. The crew
controls the cabin pressure by manual control of the outflow valve. This
gives the CPCS a triple redundant architecture.
The CPCS provides positive pressure relief to avoid damage to the aircraft
due to positive over pressure. When the differential pressure exceeds the
maximum differential pressure of 597.08 hPa (8.66 psi), the CPCS software
control logic opens the outflow valve. This function is only available in the
automatic mode of operation.
Whenever the differential pressure exceeds the nominal differential pressure by +4 hPa (+.06 PSID) the control logic will automatically open the outflow valve to limit differential pressure (available only in AUTO mode).
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Revision: 00
An additional Independent control function will open the outflow valve if the
nominal differential pressure +20 hPa (+.29 PSID) is reached. This function
is available in both Auto and Manual modes.
A pneumatically actuated safety valve is also used to limit differential positive pressure to +597 hPa (+8.66 PSID )
Auto pressure control loop
The CPCS controller controls the cabin pressure by generating a speed
command for the outflow valve. The outflow valve maintains a safe cabin
pressure by modulating the rate at which the air flows out of the cabin.
The CPCS controller calculates a cabin reference from the ambient pressure
(PA) and inputs from the FMS.
The difference between the reference pressure (PC REF) and the actual
cabin pressure (PC ACT), named DELTA PC, produces a speed and direction command for the motor interface. The motor interface directly controls
its associated motor of the outflow valve.
For BITE purposes and cockpit indication on EICAS, the position of the outflow valve is taken from one channel of a dual potentiometer. Speed control
is achieved via a motor revolution counter fed by signals from the three hall
sensors in the motor.
FOR TRAINING ONLY
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Chapter 21-30
Page 7
Figure 4: The cabin pressurization controller
CH 1 (OR 2)
ARINC INPUTS FROM MAU 1 & MAU 3
-Baro correction
-Cruise flight Level
-WOW, engine , door discretes
-Gross weight
-Landing field elevation
-Ambient pressure
DISCRETE INPUTS FROM FD PANEL
-Dump switch
-Ditch switch (If installed)
-Manual command
-Mode selector
-LFE selection
ANALOG INPUT FROM OUTFLOW VALVE
-Potentiometer feedback
-Motor hall sensor signals
ARINC OUTPUTS TO MAU 1 & MAU 3
-Airfield altitude
-BIT fault matrix (EICAS,CMC)
-Cabin diff pressure, pressure rate
-Cabin altitude
-Channel status word
-Landing field elevation
-Outflow valve position
DISCRETE OUTPUTS TO MAU 1 & MAU 2
-Automatic mode fail
-Manual mode fail
-Safety valve status
DISCRETE OUTPUT TO FD PANEL
-28VDC Power (for ditch,dump,manual)
ANALOG OUTPUT TO OUTFLOW VALVE
-Motor power signals
-Potentiometer power supply
-Hall sensor power supply
OFV Position Feedback
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190
The CPCS controller provides automatic cabin pressure control. It also performs BITE power-up, continuous and initiated tests. The CPCS controller is
installed in the forward avionics compartment. It has four built-in pressure
sensor ports, two for each control channel.
One sensor of the control channel is used for the control loop and indications, the other is used as a backup for safety functions and indications. Four
electrical connectors, two on each end of the unit, provide interconnection to
other aircraft systems.
The independent control channels communicate via an internal CAN (Controller Area Network) bus and internal discrete signals. Each control channel
is powered by two separate aircraft power supply sources for redundancy.
Channel one is powered by the 28 VDC (Volt Direct Current) essential buses
1 and 2. Channel two is powered by the 28 VDC essential buses 1 and 3.
The CPCS controller is part of a dual redundant system. It is active when the
system operates in the automatic mode. Only one control channel operates
the outflow valve at any given time. The other control channel is in hot standby. Pressure sensor signals are transmitted via ARINC 429 to the control circuits and are used for cabin pressure control logic. The control channel
calculates a reference value for cabin pressure from external aircraft inputs
and internal logic.The reference value is compared with the actual cabin
pressure and when a difference exists, an error signal is output.This error
signal is fed to one of the motors in the actuator to drive the outflow valve to
the desired position.
• Fail state
The initialization state performs these tasks:
• Power-up BIT (Built-in Test)
• Initialization of software
• Initialization of hardware
• Control channel determination for flight
• Resets all flight indications
• Initialization of pressure control loop
• Synchronisation to the other control channel
• Start normal control function
In the stand-by state, the control channel switches off drive power to the outflow valve and some system performance monitoring tests are disabled. If
no faults are detected and manual mode is not selected, the pressure control
loop and the position control loop are held initialized to actual values. This
achieves a smooth transfer to the operational state in respect to cabin pressure rates.
In the fail state, the control channel switches off drive power to the outflow
valve because faults have been detected. All outputs to other aircraft systems are flagged invalid except ARINC information about the status of the
system.
In the operational state, if the control channel detects no faults and all BIT
functions are enabled, the pressure control is activated.
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Chapter 21-30
Page 9
Figure 5: Fwd E-Bay compartment access
Forward E-Bay Compartment Access
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Chapter 21-30
Page 10
190
The Cabin Pressure Control System modes
During ground and flight operation the CPCS determines the current flight
mode depending on ARINC information. The system operates with the following flight modes:
• Ground (GN)
• Takeoff (TO)
• Climb (CI, CE)
• Cruise (CR)
• Descent (DI)
• Abort (AB)
The mode logic uses the following information from the MAU (Modular Avionics Unit) to determine the current flight mode:
• Landing gear status and validity (generated by FADEC (Full-Authority
Digital Engine-Control)
• Engine takeoff power status and validity (generated by FADEC)
• Ambient pressure (generated by ADC)
• Cruise Flight Level (CRFL) and validity (generated by FMS)
The flight mode transitions for a normal flight are as follows:
• Ground Mode - The ground mode is active when the landing gear status
shows that the landing gears are compressed and the engines takeoff
power signals are not set.
• Ground to Taxi Mode - The taxi mode becomes active as soon as the
doors signal indicates the doors are closed and both engines rotation
(N2) are higher than 60%. This mode is only possible to be activated from
the ground mode.
• Climb Mode to Abort - If the aircraft stops climbing and begins an immediate descent, the CPCS interprets this as a flight abortion.The abort is
only possible if the cruise mode has not been entered and either the aircraft is below 10000 ft absolute or is less than 5000 ft above the takeoff
field.
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Chapter 21-30
Page 11
Figure 6: Ground and takeoff modes
MODE
GROUND
TRANSITION INDICATOR
TARGET CABIN PRESSURE
RATE
•WOW SIGNAL PRESENT
•NO ENGINE POWER SIGNAL
0.7 hPA LOWER THAN SENSED CABIN PRESSURE
(OUTFLOW VALVE COMMANDED FULL OPEN)
+500 SLFPM INCREASING
-300 SLFPM DECREASING
MODE
TRANSITION INDICATOR
TARGET CABIN PRESSURE
RATE
TAXI
•WOW SIGNAL PRESENT
•DOORS CLOSED
•N2 > 60%
=AMBIENT PRESSURE + 7.5 hPA
(OUTFLOW VALVE CLOSES CPCS
TAKES CONTROL)
+300 SLFPM INCREASING
-300 SLFPM DECREASING
Cruise
Ground
Taxi
Climb
Takeoff
Descent
CPCS Flight Mode Logic
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190
Climb and Cruise modes
• Climb external is used when a valid CRFL is received from the FMS.
Climb internal is used if the CRFL is invalid or the FMS fails.
• Climb Mode to Abort - If the aircraft stops climbing and begins an immediate descent, the CPCS interprets this as a flight abort. The abort is only
possible if the cruise mode has not been entered and either the aircraft is
below 10000 ft absolute or is less than 5000 ft above takeoff field.
• Climb Mode to Cruise - In the climb external mode, the mode logic switches from climb to cruise when the aircraft reaches the planned CRFL. In
the climb internal mode, the mode logic switches from climb to cruise
when the aircraft stops climbing.
• Cruise Mode to Descent - The descent mode becomes active when the
aircraft starts descending after the cruise.
• Descent to Ground - The ground mode is active when the landing gear
status indicates that the aircraft is on the ground.
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Chapter 21-30
Page 13
Figure 7: Climb and cruise modes
MODE
TRANSITION
INDICATOR
CLIMB INTERNAL
(NO CRFL AVAILABLE)
•WOW SIGNAL
NOT PRESENT
CLIMB EXTERNAL
(VALID CRFL AVAILABLE)
TARGET CABIN PRESSURE
RATE
CALCULATED VALUE BASED ON
AMBIENT PRESSURE
+750 SLFPM INCREASING
-500 SLFPM DECREASING
CALCULATED VALUE BASED ON
CRFL, NOMINAL ∆P*, AND
SELECTED LFE.
*NOM ∆P 535.99 Hpa FOR CRFL<37k
*NOM ∆P 535.99 Hpa FOR CRFL>37k
INCREASE RATE BASED ON AIRCRAFT
GROSS WEIGHT AND AMBIENT PRESSURE
AT TAKEOFF FIELD ALTITUDE
-500 SLFPM DECREASING
Cruise
Ground
Taxi
Climb
Takeoff
Descent
CPCS Flight Mode Logic
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190
Descent and Abort modes
The CPCS will transition to DESCENT mode by selecting the landing field
altitude before the aircraft leaves the cruise flight level. The target pressure
will be set to landing field altitude plus 0.12 psi to ensure landing with the
CPCS in control. Cabin rate of change depends on cabin pressure, landing
field pressure and ambient pressure within 200 and 750 fpm.
If the aircraft stops climbing and begins immediate descent, the CPCS transits to ABORT mode. This transition is only possible from climb mode when
the aircraft altitude is below 10000 ft absolute or 5000 above the takeoff
field. In this mode, cabin pressure will be scheduled back to the take-off altitude, with a 5000 fpm rate of change.
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Chapter 21-30
Page 15
Figure 8: Descent and abort modes
MODE
TRANSITION INDICATOR
TARGET CABIN PRESSURE
RATE
DESCENT
•START OF AIRCRAFT
DESCENT BASED ON
ALTITUDE CHANGE
•BASED ON SELECTED LFE
BASED ON CABIN PRESSURE, LANDING FIELD
PRESSURE AND AMBIENT PRESSURE
MODE
TRANSITION INDICATOR
TARGET CABIN PRESSURE
RATE
•AIRCRAFT REACHES CRFL
(CLIMB EXT MODE)
•AIRCRAFT STOPS CLIMBING
(CLIMB INT MODE) BASED
ON ALTITUDE
•CLIMB EXT ⇒ CRUISE
PRESSURE CALCULATED IN
SAME WAY AS CLIMB EXT
MODE
•CLIMB INT ⇒ CRUISE
PRESSURE BASED ON
AMBIENT PRESSURE AND ∆P
AT TIME OF CLIMB/CRUISE
MODE CHANGE..
+500 SLFPM INCREASING
-300 SLFPM DECREASING
CRUISE
Cruise
Ground
Taxi
Climb
Takeoff
Descent
CPCS Flight Mode Logic
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Manual mode
The manual mode of operation gives the flight crew manual control of the
cabin pressure.
When the MODE selector switch on the pressurization control panel is in the
MAN position, it configures the CPCS for manual operation. Both automatic
channels revert to the stand-by state. The manual operation is performed by
one control channel which is selected automatically. The crew has direct
manual control of the outflow valve via the CABIN ALT switch on the pressurization control panel.
The CPCS detects any failure in the manual mode and provides fault messages to the EICAS and CMC (Central Maintenance Computer).
The EICAS shows the message “PRESN MAN FAIL” if the manual function
of both channels has failed.
Failures detected during flight which do not require crew action are displayed on the CMCM (Central Maintenance Computer Module) after landing.
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Figure 9: Manual mode
AUTO CHANNELS
REVERT TO STANDBY
MANUAL MODE
Max Delta-P Limitation (+29
PSID above nominal) provided
by independent logic
Max Delta-P limitation Only
No Altitude limit
No Automatic Ground Depressurization
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Built-in Test
The CPCS controller has BIT logic to detect failures within each control
channel or in the CPCS functions. If the BIT logic detects a fault in the active
control channel, the control channel goes into automatic fail. The CPCS
switches automatically to the other control channel without any workload to
the crew. A channel Fail message is displayed on the CMC display.
All detected faults are stored in NVM (Non-Volatile Memory) and can be
down loaded for maintenance purposes off-wing. All faults are continuously
transmitted to EICAS and CMCM via the ARINC 429 output bus.
The CPCS checks internal parameters and functionality. The internal fault
detection logic detects and isolates single LRU (Line Replaceable Unit) and
interconnection failures that cause loss of functionality or redundancy.
The CPCS performs these tests:
• Power-up test
• Continuous hardware and software tests
• Continuous function tests
The power-up test is done after a cold start, a reset or a power supply interrupt. During the power-up test internal devices initialize and check the hardware and software of the CPCS. When the test has passed, the main page
is shown on the EICAS display. When the power-up test fail, the PRSN
AUTO FAULT message is displayed on the EICAS.
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Figure 10: Built-in Test
PRESN AUTO FAULT
Continuous Communication
MAU ,ADS,FMS ARINC Comm
ICDL test
Discrete Info word test
Landing gear input
Continuous Hardware BIT
Analog digital converter checks
ARINC power supply checks
ROM CRC/ RAM tests
Pressure sensor signal/check sum
OFV Potentiometer tests
Watchdog timer
Power On
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NO
Both AUTO
Channels ?
Pass
Continuous Function BIT
Position Loop Closure
Cabin Pressure rate
OFV Position/Drive direction
Low power Input voltage
Press Sensor Comparison
PRESN AUTO FAIL
YES
NO
Manual Channel
Fail
YES
Controller Power On BIT
ARINC Read / Write
NVM Data Range test
LRU P/N Compare test
Watch hardware test
Pressure Sensor Calibration
Current/high side checks
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NO
Both Channel s
YES
PRESN MAN FAIL
Chapter 21-30
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190
Outflow valve
The outflow valve controls the air flow out of the aircraft fuselage. It is installed on the forward fairing bulkhead.
The outflow valve consists of a valve body and a rotary actuator. The valve
body comprises a 8.5 in diameter butterfly valve, a two-piece butterfly valve
flap, a splined shaft and an actuator housing.
The valve body, valve flap and actuator housing are made of anodized aluminium alloy. The valve flap is bolted around the splined shaft and moves to
the closed if loss of mechanical actuation occurs.
The rotary actuator consists of two brush less DC (Direct Current) motors, a
gear train and a dual channel potentiometer.
Each DC motor is controlled and monitored by a separate channel of the
CPCS controller. Only one DC motor drives the outflow valve at any time.
Both DC motors use the same actuator mechanism.
The gear train consists of two irreversible worm screws, a differential gear
stage and two stages of spur gears. The worm screws are linked directly to
the output shafts on the DC motors. The spiral angle of the worm screw prevents back driving of the motors.
The dual potentiometer sends a position signal to each control channel of
the CPCS controller. This provides position feedback of the outflow valve in
automatic and manual modes of operation.
The CPCS has a fail-safe software logic to close the outflow valve if the cabin pressure altitude reaches 14500 ft. This function overrides the normal automatic operation only, it does not effect the manual operation of the outflow
valve.
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Figure 11: Outflow valve
Looking Aft from Forward Cargo Compartment
Cabin Outflow Valve located on forward
fairing bulkhead
45 DEG
CONTROL
14,500 FT
12,700 FT
Control features are independent of normal pressure control logic
Not available in manual mode
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190
The positive pressure relief valve
The positive pressure relief valve is a pneumatically actuated gate valve, located on the rear pressure bulkhead, normally held in the closed position by
a pre-loaded spring.
Valve operation is independent of the Cabin Pressure Control System controller. The relief valve provides both positive and negative pressure relief. It
contains a pilot valve that compares cabin pressure to ambient pressure.
If the pressure difference exceeds 8.66 psid, the pilot valve will open and the
differential pressure will act on the diaphragm to open the valve.
A micro switch is mounted on the valve to provide input to the Modular Avionics Unit for status reporting. The static port connects the positive pressure
relief valve to ambient pressure.
The port is located at the rear fuselage section and has an integral heater
powered by 28 VDC to eliminate ice blockage.
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Figure 12: Positive pressure relief valve
POSITIVE PRESSURE
RELIEF VALVE
28 VDC
I
HEATER
STATIC
PORT
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Negative pressure relief
Under normal flight conditions, the valve is in the closed position. The valve
is mechanically actuated using the self-balanced spring forces at the valve
gate and the ambient-to-cabin differential pressure. If the ambient pressure
exceeds the aircraft cabin pressure, the valve gate opens and limits the negative pressure. The springs set the cap to open at a differential pressure of
-10 hPa (-0.15 psi). The valve is fully open at -35 hPa (-0.51 psi).
The safety valve has also a negative relief function. If the ambient pressure
acting on the underside of the gate valve exceeds the cabin pressure, the
gate valve opens allowing air from ambient to flow into the cabin.
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Figure 13: Negative pressure relief
NEGATIVE PRESSURE
RELIEF VALVE
limits maximum negative pressure differential to 0.5psi
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190
EICAS indications
In case of a Cabin Pressure System fault, EICAS messages are displayed:
• If one controller channel fails, the EICAS advisory message
PRESN AUTO FAULT will be displayed
• If both controller channels fail, the EICAS caution message PRESN
AUTO FAIL will be shown
• When both channels are unable to operate in manual mode, the
caution message PRESN MAN FAIL will be displayed
• If cabin altitude exceeds 9700 ft, a warning message HI CABIN ALT
will illuminate, and an aural warning, CABIN, will sound.
The EICAS Display also provides a continuous status of cabin altitude, cabin
rate, differential pressure, and landing field elevation.
Display color indicates current status of displayed value.
Green - Normal range
Amber - Advisory range
Red
- Warning
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Figure 14: EICAS indications
(2 second Delay)
CPCS Controller AUTO FAIL Channel 1
CPCS Controller AUTO FAIL Channel 2
AND
PRES N AUTO FAIL
(2 second Delay)
CPCS Controller AUTO FAIL Channel 1
OR
CPCS Controller AUTO FAIL Channel 2
PRES N AUTO FAULT
(2 second Delay)
CPCS Controller MANUAL FAIL Channel 1
CPCS Controller MANUAL FAIL Channel 2
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AND
PRES N MAN FAIL
Chapter 21-30
Page 28
190
AMBIENT
PRESSURE FROM
MAU1 MAU2 MAU3
Cabin Differential Pressure >8.5 psid
Cabin Differential Pressure <-0.3
psid
OR
CABIN DIFF PRESS
FAIL
CABIN
PRESSURE
Cabin Altitude 14,500 +250/-500 Feet
Cabin Altitude >9,700 Feet For Airfield
Operations <9,400 Feet
Or
Airfield Altitude +500 Feet For Airfield
Operations >9,400 Feet
OR
CABIN ALTITUDE HI
Aural
Warning
“CABIN”
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Figure 15: EICAS indications
LFE:
3000
CTRL 2700
Cyan (CTRL)
Manual
Green- FMS
93. 8
T 0- 1
T/
OFF
94. 0
OFF
N1
0. 0
26°
I TT
T
0. 0
FF PPH0. 0
0. 0
11 12 1
5520
DN
VP
1
45°
SLA
LAT/ FLA
LAP/ SPD
DBRK
APU
48°
T MP
TE
L
LP
HP
F
FU
ULL
DN
MODE
AUTO
STOP
CLOSE
OPEN
DN
LFE
CTRL
MAN
OFF
ALT
RATE
P
9800
200
8. 32
FT
FPM
PSI
LFE
2915
FT
TRI MS
TR
SPD
DBRK
S
PRESSURIZATION
OUTFLOW
LANDI NG GEAR
LA
11030
PRE
RESS
Cyan Dash
Invalid Data
HI CABIN
PRESN MAN FAIL
PRESN AUTO FAIL
PRESN AUTO FAULT
FU
UEL QTY
OI L
Green Dash
Man Mode
28°
N2
FQ LB
L
------
0. 0
0. 0
5510
-------
ROLL
RO
DUMP
LFE
-
+
PI TC
TCH
0
S F
S/
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21-40 Heating
Introduction
The door sill heaters are electric heating pads located in the forward and aft
doorway entrances, attached to the floor panels. These pads provide heating during cold weather icing conditions, to prevent snow accumulation at
the door entry. The unit includes:
• a panel shaped to fit the mounting holes,
• an internal heating element and
• a temperature control sensor.
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Page 1
Figure 1: The door sill heaters
Heating element
temperature control sensor
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190
Floor panel heaters operation
The floor panel heaters operate when the aircraft is on the ground with the
doors open, and an outside air temperature below 40°F/4.4°C.
The power source to the heater is 115v single phase AC.
If the ambient temperature increases above 45°F/7.2°C or if the door is
closed, the power to the heater will be disconnected. When the heating element is powered, the internal thermostat will regulate the temperature.
If internal temperature rises above 68°F/20°C, the thermostat will open and
disconnect heating. If the temperature drops below 59°F/15°C, the thermostat will close the circuit and heating will begin.
An over temperature protection switch is included in the circuit. The switch
will disable heating on rising temperature of 149°F/65°C, and it will reset if
panel temperature drops below 104°F/40°C. In case of heater failure, a message is generated on the CMC.
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Figure 2: Floor heating operation
The floor heaters operate if:
An outside air temperature below 40°F/4
The aircraft is on ground
With the doors open
115 V single phase AC
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The floor panels heaters construction
The heating panel is a Kapton foil heater bonded to an aluminium cover and
skin. This construction provides a thin flexible heating element. Epoxy adhesive is used to bond the Kapton foil to the metal element, to prevent moisture
penetration.
The foil heater is rated for continuous use at 302°F/150°C, which is well
above the normal operating temperature of the mat.
The heated floor panels have an electrical lead of sufficient length to allow
easy removal and installation.
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Figure 3: The floor panel heaters construction
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21-50 Cooling
Introduction
The air conditioning system utilizes two identical cooling packs that provide
condition bleed air for cabin heating and cooling.
The packs provide condition bleed air for cabin heating and cooling, and include the following components:
•
•
•
•
•
•
Dual heat exchanger,
Air cycle machine,
Condenser-reheater,
Water collector,
Add heat bypass valve and
temperature sensors.
There are also two external components:
• The Pack bypass valve, and a
• Pack flow control valve which together control pack operation.
During normal operation, each cooling pack provides half of the total fresh
airflow; however, a single pack is capable of providing 67% of the total flow
and ensuring safe aircraft ventilation and temperature control capability.
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Figure 1: The air conditioning system
Low Limit Valve
Air Cycle Machine
Condenser / Reheater
Fan Inlet Diffuser Housing
Water Collector
Add Heat Valve
Spray Nozzle
Ram Inlet Duct
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Pack Outlert Duct
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ECS pack
The air conditioning system utilizes two identical air cooling packs, right and
left, to condition bleed air for cabin heating and cooling. Each air cooling
pack consists of a dual heat exchanger, air cycle machine, condenser/reheater, water collector, valves and temperature sensors. The primary function of the air cooling pack is to supply conditioned air to the cabin
distribution system for environmental control. The air cooling pack also contains an internal condensing water collection system which removes moisture from the cooling pack air flow. Hot air from the engine bleed system is
precooled in the dual heat exchanger using cold ram (outside) air to remove
the heat. An air cycle machine within the pack contains two cooling turbines
which generate cold air, through expansion, for cooling cabin.
The high air exchange rate is necessary to control temperature gradients,
prevent stagnant cold areas, and maintain air quality.
The cooling pack system conditions hot bleed air for cabin air conditioning.
There are two identical cooling packs (right and left) per aircraft and they are
located in the ECS (Environmental Control System) pack bay in the forward
fairing of the aircraft.
The cooling pack is an air cycle refrigeration system that uses air passing
through and into the airplane as the refrigerant. The cooling pack system automatically controls the temperature and decreases the humidity of the cockpit and cabin air. The two cooling packs, which are installed in the forward
part of the wing-to-fuselage fairing, provide dry, sterile, and dust free, conditioned air to the flight deck and passenger cabin at the proper temperature,
flow rate, and pressure to satisfy pressurization and temperature control requirements.
An equal quantity of filtered, re circulated air is mixed with air from the cooling packs.
A flow control valve regulates flow of bleed air into the air conditioning packs.
The refrigeration pack is out fitted with sensors and valves for temperature
and operational control, and heat exchangers that use outside ram air for excess heat dissipation.
An equal quantity of filtered re circulated air is mixed with air from the air conditioning packs. The high quantity of supply air results in a complete cabin
air exchange about every 2.5 to 3.5 minutes (based on aircraft configuration
and altitude), or about 18 to 25 times an hour.
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Figure 2: ECS pack
GROUND
CONNECTION
Ovb d
P rim a ry
He a t
Exc h a n g e r
RAM air
Em e rg
Ra m
S e c o n d a ry
He a t
Exc h a n g e r
Co n d e n s e r
Re h e a te r
RAM AIR INLET
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The flow control valve
The pack flow control valve is located upstream of the left and right air cooling packs.
The valve is torque motor controlled and modulated by the AMS controller,
but has a pneumatically actuated butterfly valve. It incorporates a closed position switch to provide position feedback to the AMS controller. A filter removes air supply contaminants.
A locking screw installed in the actuator housing can be used to lock the
valve in a closed position.
The valve operates as follows:
• the flow sensing venturi differential pressure signal is sent to the
AMS controller for calculation. For internal calculation, the AMS
also uses the manifold bleed pressure and the pack inlet temperature to determine air flow to the packs. The controller millivolt signal
is sent to the flow control valve to define the valve position that will
modulate the air flow.
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Figure 3: The flow control valve
Torque motor
Spring force
Supply pressure
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Butterfly disc
Chapter 21-50
Page 6
190
The flow sensing venturi
The flow sensing venturi is a steel duct. The venturi contains pressure-sensing ports on the upstream and downstream side of the duct orifice. Airflow
across this duct is measured by a differential pressure sensor mounted on
the venturi and is used by the AMS Controller to calculate the air flow.
The sensor provides a zero to 10 volt DC electronic signal to the AMS controller. The sensor is hermetically sealed and has two input pressure ports,
an internal pressure transducer and an electric connector.
Venturi Delta-P sensors
The differential pressure sensor is mounted on the flow sensing venturi duct
directly upstream of the pack flow control valve. The sensor provides a 0 to
10 VDC (Volt Direct Current) electronic signal to the AMS controller, which
is used to calculate the air flow that goes into the environmental control system. The sensor is hermetically sealed and consists of two input pressure
ports, and internal pressure transducer, and an electrical connector. There
are two differential pressure sensors per aircraft (one per cooling pack).
Air conditioning pack flow controls
The flow of air to the air conditioning packs is measured using a differential
pressure sensor which is mounted on a venturi duct. The differential pressure sensor sends an electronic signal to the AMS controller. The AMS controller uses the differential pressure, the bleed manifold pressure, and the
pack inlet temperature to calculate airflow going to the air conditioning pack.
The AMS controller then supplies a torque motor current command to modulate the pack flow control valve to obtain the desired pack airflow rate.
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Figure 4: The flow sensing venturi
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190
The dual heat exchanger
ceeds the ACM fan outlet pressure. This fan bypass function is necessary to
prevent ACM damage caused by excessive fan surge margins. There are
two fan bypass check valves per aircraft (one per cooling pack).
A dual heat exchanger and a fan inlet diffuser housing assembly are installed into each ECS pack.
The heat exchanger has three different circuits:
• The primary circuit removes heat from bleed air before entering the
compressor section. The primary section is a single-pass cross flow
configuration.
• The secondary circuit removes heat from the compressor outlet air
before it goes towards the reheater. The secondary section is a
two-pass cross-counter flow configuration.
• Both bleed circuits are cooled by ram air in series - first the secondary then through the primary heat exchanger sections.
Ram air exiting the heat exchangers enters the fan inlet diffuser housing and
is either pulled through to ambient by the fan or passes through the fan bypass check valve.
The heat exchanger contains access windows for inspection and cleaning of
the heat exchanger ram air circuit.
Fan bypass check valve
The fan bypass check valve is a 12 in diameter hinged, petal-type check
valve which has six petals that cover six orifice windows in a single valve
seat. The valve allows airflow through the orifice windows in one direction.
Flow in the opposite direction (reverse flow) is prevented by the petals closing on the aluminium check valve frame.
The fan bypass check valve is installed in the cooling pack between the fan
inlet diffuser housing and the ram air outlet duct, and allows ram air to bypass the air cycle machine fan whenever pressure in the ram air circuit ex-
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Figure 5: The dual heat exchanger
ECS PACK
Bypass check valve
T
T
Primary
Secondary
Condenser
Reheater
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190
The air cycle machine components
The air cycle machine provides the source for pack cooling. The external
structure consists of a fan and compressor housing, a first stage turbine
housing, and a second stage turbine housing. Each housing is made of cast
aluminium.
The ACM internal structure has two turbine rotors which drive a compressor
rotor and a cooling fan rotor.
The four rotors and two shaft segments turn as one assembly locked together by a tie rod.
The assembly rotates in a pair of hydrodynamic, foil-type journal bearings.
Axial movement is limited by a pair of hydrodynamic thrust bearings. These
hydrodynamic foil-type bearings use no oil and require no scheduled maintenance.
The fan rotor is attached to one end of the assembly and is positioned adjacent to the fan shaft segment followed by the compressor rotor, first turbine
rotor, turbine shaft segment, and second turbine rotor. The turbine shaft segment includes both a journal bearing surface and the thrust disk on which
the two bearings act.
A tie-rod goes through the centre of the shaft and rotor segments and holds
the assembly together axially. The tie-rod is assembled with a high preload
which permits all components of the assembly to operate as a one shaft system.
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Figure 6: The air cycle machine components
2 turbine stages
Fan and compressor housing
First stage turbine housing
2 compressor stages
Second stage turbine housing
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190
Air cycle machine operation
Air is cooled in the primary section of the dual heat exchanger using ram air
to remove the heat. The air is then compressed by the compressor portion
of the dual turbine ACM. The heat generated by compression is removed by
the secondary portion of the dual heat exchanger, using ram air. The air is
then passed through the condenser/reheater where it is sub-cooled within
the condenser using the cold exhaust air from the first stage turbine. This
cooling process condenses water from the air to permit it to be collected by
the water collector. The collected water is moved to the spray nozzle, which
is located in the secondary ram inlet header of the dual heat exchanger.
The water is sprayed on the ram air face of the core to increase the heat exchanger performance through evaporative cooling. After exiting the water
collector, the air flows through the re-heater portion where it is preheated to
increase first stage turbine performance.
After expansion through the first stage turbine portion of the ACM, the air
passes through the cold side condenser portion of the condenser/ reheater
where it removes the heat for condensation. After exiting the cold side of the
condenser, the air enters the second stage turbine of the ACM where it is
expanded to provide the cold air source for cabin cooling.
The condenser inlet temperature is continuously monitored by the AMS controller using electronic feedback from the condenser inlet temperature sensor. The condenser inlet temperature is controlled by adding warm
compressor outlet air to the condenser inlet airflow. This is achieved by modulation of the low limit valve and/or the opening and closing of the add heat
valve. The condenser inlet temperature is controlled to 34 °F/ 1.1°C under
most pack operating conditions to prevent water from freezing in the condenser. In certain low humidity conditions the condenser inlet may be controlled to 50 °F/ 10 °C. Pack outlet temperatures are continuously monitored
by the AMS controller using electronic feedback from the pack outlet temperature sensor. The pack outlet temperature is controlled by adding hot
pack inlet air to the pack outlet airflow. This is accomplished by modulation
of the pack bypass valves. The AMS controller reads actual pack outlet temperatures and sends a torque motor current command to modulate the pack
bypass valves to obtain the desired pack outlet temperatures.
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Figure 7: Air cycle machine operation
P=41
T=447
T=447
WF=4
P=15
T=255
P=58
T=447
P=32
T=-32
P=40
T=188
P=41
T=447
P=56
T=272
P= 54
T= 84
P=32
T= 34
P=15
T-3
P=15
T=30
P=31
T=62
P=55
T=-53
P=55
T=-53
P=15
T= 90
ACM SPEED: 39,000 RPM
T=Temperature Degrees F
P=Pressure PSIA
WF=Flow PPM
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190
Condenser/Reheaters
The condenser/re-heater is an aluminium dual-heat exchanger consisting of
headers and mounts welded to a core. Both core sections are single pass,
cross flow, plate-and-fin designs. The condenser cold circuit is situated between the two turbine stages of the air cycle machine and is never subjected
to sub-freezing air temperatures, therefore, it does not require complicated
features for the prevention of ice buildup, which other systems using the
conventional chilled re circulation cycle demand.
Water collectors
The water collector is a brazed and welded assembly. The collector body is
constructed of two aluminium-brazed sub assemblies welded together at the
outside diameter. Each section of the sub assembly is made of spun and hydro-formed sheet metal parts.
The water collector removes water from the condenser/reheater heat exchanger and sends the dry air to the air cycle machine. A swirl vane at the
water collector inlet sends the water to the duct walls. A clearance between
the diffuser section and the air return diffuser section catches most of the
water from the airflow. A drain boss located at the lowest section of the collector lets water drain by gravity and air pressure. An overflow drain boss located slightly above the lowest point lets water drain if the primary port is
clogged.
Water spray nozzles
The water spray nozzle is mounted in the ram air inlet ducting directly upstream of the dual heat exchanger. Water, which is collected in the water
collector, is routed through drain line to the water spray nozzle. The water
spray nozzle sprays the water on the ram inlet face of the secondary heat
exchanger. This cools the air that goes into the secondary heat exchanger
and improves heat exchanger performance.
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Figure 8: The condenser
T1
T2
T
Water collector
Primary
Condenser
Reheater
Secondary
RAM AIR INLET
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190
The bypass valve
The pack bypass valve is installed parallel to the air conditioning packs. It is
a butterfly valve powered by a pneumatic actuator.
The valve maintains the required hot air flow to the pack outlet, as directed
by the downstream duct supply temperature sensor output, which directs the
pack controller to modulate current to the valve's torque motor.
The valve position is controlled by the pneumatic servo pressure generated
by the torque motor. The valve can be locked in the closed position by removing the lock bolt.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 17
Figure 9: The bypass valve
ECS PACK
BYPASS VALVE
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 18
190
Add heat, and low limit bypass valve
Bleed air passing by the pack inlet temperature sensor and through the primary heat exchanger enters the air cycle machine compressor.
Compressor inlet and outlet temperature is sensed by temperature sensors
and forwarded to the AMS controller.
The main flow from the compressor goes through the secondary heat exchanger and on to the condenser/reheater. Some hot air is tapped and directed to the Add Heat Valve to maintain turbine second stage inlet
temperature.
Air from the condenser/reheater is directed to the first stage turbine, where
the temperature will drop.
The Low Limit Bypass Valve is installed parallel to the first stage turbine. The
valve provides additional warm air to maintain condenser inlet temperature.
Air flows through the condenser and enters the second stage turbine for a
further temperature reduction.
A linear actuator is used to rotate a piston that meters the amount of warm
air bypass flow, in order to control condenser inlet duct temperature. The
downstream duct temperature is used as feedback for positioning of the
valve.
The AMS control logic is based on BUMP/STOP/CHECK, and the signal is
sent to the actuator to extend or retract in steps. A knob on the linear actuator housing permits manual valve position adjustments.
Add heat valve
Each air conditioning pack incorporates an ON/OFF Add Heat Valve which
supplies warm air from the compressor outlet to the condenser inlet. This is
used to maintain a minimum turbine inlet temperature of 15.5 +C/60 °F.
The Add Heat Valve is controlled by the AMS controller as a function of ambient temperature and altitude, and is opened and closed using a solenoid.
Turbine outlet cold air is mixed with pack bypass air to achieve the requested duct temperature.
The low limit bypass valve
The Low Limit Bypass Valve is an electrically-actuated valve installed on the
air cycle machine turbine housing.
The valve limits condenser inlet temperature to a minimum of 1.1 °C/34 °F
up to 25000 ft, or to 10 °C/50 °F above 25000 ft.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 19
Figure 10: The low limit bypass valve, Add heat valve and ECS pack bypass valve
ECS pack bypass valve
Low limit bypass valve
Add heat valve
GROUND
CONNECTION
Ovb d
P rim a ry
He a t
Exc h a n g e r
Em e rg
Ra m
S e c o n d a ry
He a t
Exc h a n g e r
Co n d e n s e r
Re h e a te r
RAM AIR INLET
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 20
190
Temperature sensors
The air conditioning pack temperature control has five temperature sensors,
which supply data to the AMS controller.
The sensors are:
•
•
•
•
•
Pack inlet temperature sensor,
Compressor inlet temperature sensor,
Compressor outlet temperature sensor,
Condenser inlet temperature sensor and
Pack outlet temperature sensor.
All of these sensors are dual element sensors (except the pack inlet temperature sensor, which has a single element) in order to improve system reliability. The AMS controller monitors all sensor voltages in order to control
pack operation or determine pack failure.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 21
Figure 11: Temperature sensors
Test Inhibits
Invalid temp sensor signals
Minimum Pack Flow
PBV position limit
Compressor Outlet Temp exceeds
Compressor Inlet temp by 30 Deg
F Min for 2 Minutes, and Aircraft
In Air
OR
Condenser Inlet temp greater than 180
Deg F and Pack Outlet Temp greater
than 120 Deg F 10 seconds, and
Aircraft on Ground
CONDENSER
INLET TEMP
COMPRESSOR
INLET TEMP
ACM FAIL
Issue: Aug05
Revision: 00
PACK
OUTLET TEMP
COMPRESSOR
OUTLET TEMP
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 22
190
ECS Off Request
The FADEC may send an ECS OFF signal to the AMS controller, requesting
that no bleed air be extracted from the engine for the air-conditioning system. The FADEC sets this signal depending on the TDS input (REF ECS
OFF), pressure altitude, flight phase and engine failure detection.
If the ECS is bleeding air from the engine and the FADEC ECS OFF request
is true and Altitude is below 15 000 ft, both ECS packs will be commanded
OFF. The ECS cooling packs will be shut down at -30 ppm/ sec after receiving the ECS OFF signal from the FADEC. The APU can be used as a valid
bleed air source when the ECS OFF signal is set to true and Anti-ice is not
required.
In response to the ECS OFF signal the AMS controller has the following requirements:
If the FADEC transitions the ECS OFF signal from true to false, the both
ECS cooling pack FCV’s will be automatically opened without any pilot action. The AMS will disregard the FADEC ECS OFF signal if aircraft altitude
is above 15,000 ft.
In general, the AMS controller will use the ECS OFF signal from the in-control FADEC channel. If the AMS controller loses communication from one
SPDA then AMS controller will use the other SPDA as a backup source of
information for the ECS OFF and channel in control signals.
The time from the ECS OFF signal being received in the AMS controller to
ECS cooling pack FCV’s closing will be less than 5 seconds when commanded ON again by the AMS controller.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 23
Figure 12: ECS OFF LOGIC
PALT < 500ft ATOA
ECS OFF
(X-eng signal)
OEI
(local engine)
TO mode
at Thrust Set
ECS OFF
signal
TLA > TO/GA
REF ECS
OFF
TLA > MAX
TO mode
at Thrust Set
PALT < PALT ENV
GA mode
at Thrust Set
PALT < 9700ft
Issue: Aug05
Revision: 00
OEI
(either engine)
FOR TRAINING ONLY
Reproduction Prohibited
If TOPALT < 8000ft, then PALT ENV = 9700ft
else PALT ENV = 15000ft
Chapter 21-50
Page 24
190
Pack related messages
The Pack-related EICAS messages are:
• PACK FAIL CAUTION if any pack component develops a fault,
• PACK OFF advisory message if the pack is switched off, or
• PACK LEAK caution message when an overheat is detected in the
pack high pressure bleed duct.
CMC messages will be provided to determine failed pack components if the
PACK FAIL message is present.
The pack will be disabled in the following conditions:
• bleed source not available,
• pack switch is OFF,
• left or right engine start with weight on wheels,
duct leak or if the AMS built-in-test detects failure.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 25
Figure 13: Pack related messages
The pack will be disabled in the following conditions:
Bleed source not available
POWERPLANT
AMS built-in-test fail
START/STOP
Pack switch is OFF
RUN
STOP
RUN
START
STOP
1
eft or right engine start with weight on wheels
Duct leak or if the AMS built-in-test detects failure
AIRCOND / PNEUMATIC
RECIRC
CKPT
C
H
H
PACK 2
RECIRC
CKPT
C
H
BLEED 1
LEAK
Issue: Aug05
Revision: 00
APU BLEED
AUTO
OFF
1
ON
2
H
PACK 2
XBLEED
WING 2
START 2
GND
CONN
ON
PAX
CABIN
C
ATTND
PACK 1
XBLEED
WING 1
START 1
IGNITION
AIRCOND / PNEUMATIC
PAX
CABIN
C
ATTND
PACK 1
2
AUTO
OFF
START
WING 1
START 1
BLEED 2
BLEED 1
LEAK
LEAK
FOR TRAINING ONLY
Reproduction Prohibited
WING 2
START 2
GND
CONN
APU BLEED
BLEED 2
LEAK
Chapter 21-50
Page 26
190
Figure 14: Pack1 off
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 27
Figure 15: Indications
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-50
Page 28
190
21-60 Temperature control
Introduction
The temperature control system provides closed loop control for the flight
deck and passenger cabin. The cabin two-zone configuration is an aircraftselectable option.
The flight deck and passenger cabin temperatures are electronically controlled by the AMS controller between 19°C and 30°C. The AMS controller compares the actual temperature provided by the temperature sensors to the
selected temperature. If a difference exists, the AMS controller will adjust the
target duct temperature by modulating the pack bypass valve position until
the selected temperature is achieved. In case of ambient sensor failure, the
system defaults to the duct temperature sensor, and if the selector fails, the
system defaults to a 75°F/ 24°C zone temperature.
Zone Temperature Control
Cabin Zone Temperature Sensor locations.
• Cabin Zone Temperature Sensor also uses ejector to draw ambient
air across sensor element.
• Ambient air is drawn from space between overhead bins.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 1
Figure 1: The AMS temperature controller
AMS
Map
Pl an
CKPT
Sys t ems
ECS
15
FWO CAB
AFT CAB
CKPT
15
FWD CAB
AFT CAB
TCAS
Weat her
Checkl i s t
Cabin
The AMS provides temperature
control between 19° to 30°
Issue: Aug05
Revision: 00
light deck
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 2
190
Cockpit zone control
The cockpit zone receives airflow from the left air conditioning pack. Conditioned air from the left pack is mixed with the re circulated air from the left re
circulation fan. Cockpit zone control is achieved by changing the left air conditioning pack outlet temperature.
The cockpit temperature control system includes two dual temperature sensors. One sensor is located in the cockpit under the ceiling panel and the
other is in the cockpit zone duct downstream of the mixer duct. Each sensor
contains two independent sensing elements to provide signals for AMS
channels 1 and 2.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 3
Figure 2: Cockpit zone control
Temperature sensor
Temperature sensor
Channel 2
SPDA 2
Channel 1
F
F
F
(FLIGHT
DECK)
F
F
T
F
F
MIXER
F
CABIN
SAFETY
VALVES
F
OUTFLOW
VALVE
R.H.
ECS
PACK 2
(CABIN)
TO GASPERS
F
F
RECIRCULATION FAN
FAN
RECIRCULATION FAN
FILTER
FILTER
FWD
CARGO
COMPARTMENT
RECIRCULATION
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 4
190
Single cabin zone configuration
The passenger cabin receives air from the left and right air conditioning
packs, routed through the mixer duct, where it is blended with re circulated
air from the fans. Air is then routed to the front and aft passenger cabin distribution ducts. In the single cabin zone configuration, the passenger cabin
temperature is controlled by changing the right air conditioning pack outlet
temperature.
The single configuration includes two dual sensors, one ambient temperature sensor located under the cabin side panel above the floor, and the other
cabin duct temperature sensor downstream of the mixer.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 5
Figure 3: Single cabin zone configuration
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 6
190
The two cabin zone configuration
The two cabin zone configuration uses a separate trim system for independent control of forward and aft cabin zones.
Hot air is tapped from the right air conditioning pack for zone temperature
control.
The system includes:
• two trim modulating valves,
• two ejectors and
• three dual temperature sensors.
for both the forward and aft cabin zone ducts. The AMS controller will then
modulate the right pack bypass valve, via the torque motor command, to
meet the coldest cabin duct target temperature. The trim bypass valve for
the coldest zone will be sent a signal to close. The AMS controller will then
modulate the opposite zone trim modulating valve to meet the warmest cabin duct target temperature.
The trim air system utilizes two trim air modulating valves, two hot air ejectors, and associated ducting to independently control the air temperature entering the forward and aft passenger cabin distribution ducts. This is
accomplished by mixing hot air from the ejectors directly into the forward and
aft distribution duct openings within the mixing duct. The amount of hot air
flowing to the ejectors is controlled electronically by the AMS controller
through modulation of two trim air modulating valves.
The AMS will compare the actual temperature to the selected temperature
and calculate a target zone temperature for the forward and aft cabin zones.
The controller then modulate the right pack bypass valve to meet the selected coldest cabin zone duct target temperature. The cold zone trim modulating valve closes. The controller modulates the opposite trim valve to meet
the selected warmest cabin zone duct temperature.
The passenger cabin temperature is selected by the flight crew using the
PAX CABIN selector. The forward and aft passenger cabin zone temperatures can be selected by the flight attendant using CABIN TEMPERATURE
selectors located on the attendant control panels.
The passenger cabin zone requiring the coldest air is controlled by modulation of the right pack bypass valve. The opposite zone (warmest zone) temperature is controlled by modulation of the trim air modulating valve related
to that zone.
Temperature sensors located in the forward and aft cabin zone and in the
forward and aft cabin ducts provide actual temperature via electronic signals
to the AMS controller.
The AMS controller compares the selected zone temperatures to actual
zone temperatures. The difference between the selected temperature and
the actual zone temperature is used to calculate a target duct temperature
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 7
Figure 4: The two cabin zone configuration
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 8
190
Trim modulating valves
The zone trim valves regulate hot bleed flow to the trim ejectors, which are
installed in the mixer duct.
The valves are electronically controlled and pneumatically operated butterfly
valves.
The valves are fail-safe closed and can be manually locked in the closed position. The trim ejectors directionally inject hot bleed air into the forward and
aft cabin outlet ducts.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 9
Figure 5: Trim modulating valves
Compartment
recirculation
Trim modulating valves
FILTER
FAN
T
F
Forward Cabin
Mixer
Mid
E-bay
T
F
F
F
F
Muffler
Aft Cabin
Muffler
T
Outflow
Valve
FAN
FILTER
Compartment
recirculation
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 10
190
Automatic temperature control
Note that the temperature control system operates only in AUTOMATIC
mode, where:
• dual temperature sensors provide increased reliability, and
• each AMS channel is capable of controlling the entire temperature
control system.
• A CMC message is provided in case of ambient, duct sensor or trim
valve failure.
The ECS synoptic page provides monitoring of actual cockpit and passenger
cabin zone temperatures.
Issue: Aug05
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 11
Figure 6: Automatic temperature control
ZONE
131
ZONE
223
A
D
E
B
D
C
F
A
E
C
B
Issue: Aug05
Revision: 00
COCKPIT DUCT
TEMPERATURE SENSOR
F
COCKPIT ZONE
TEMPERATURE SENSOR
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-60
Page 12
190
21-MEL (Example)
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-1
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
¦ 00-01 Air Management
¦
System (AMS)
¦
Channels
C ¦ 2
¦
¦
¦ 1
¦
¦
¦ One may be inoperative provided
¦ flight is conducted at or below
¦ FL 310.
¦
¦
¦
¦ 21-04 Pilots Feet
¦
Outlet Shutoff
¦
Valves
C ¦ 2
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ 23-00 Gasper System
C ¦ 1
¦ 0
¦
¦
¦ 24-01 Recirculation
¦
Fans
C ¦ 2
¦
¦ 0
¦
¦ (M)May be inoperative provided
¦ affected fan is deactivated.
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦ 0
¦
¦
¦ (M)May be inoperative closed
¦ provided associated fan is
¦ deactivated.
¦
¦
¦
¦ 24-02 Recirculation Air C ¦ 2
¦
Filters
¦
¦
¦
¦ 0
¦
¦
¦ May be inoperative or missing
¦ provided Recirculation Fans
¦ (RECIRC) remain selected off.
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦ (M)May be inoperative or missing
¦ provided associated Recirculation
¦ Fan is deactivated.
¦
¦
¦
1) Recirculation
Fan Check
Valves
C ¦ 2
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-2
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 24-04 Recirculation
¦
System Smoke
¦
Detector
¦
¦
¦
¦
¦
¦
B ¦ 1
¦
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ (O)May be inoperative or missing
¦ provided:
¦
a) Recirculation Fans (RECIRC)
¦
remain selected off,
¦
b) Both air conditioning packs
¦
are operating normally, and
¦
c) Live animals are not carried
¦
in the forward cargo
¦
compartment.
|
|
|
|
|
|
|
|
|
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
B ¦ 1
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ (M)(O)May be inoperative or missing
¦ provided:
¦
a) Recirculation Fans (RECIRC)
¦
remain selected off,
¦
b) One air conditioning pack is
¦
operating normally,
¦
c) Live animals are not carried
¦
in the forward cargo
¦
compartment, and
¦
d) Both engine ITT margins are
¦
verified to be within
¦
limits.
|
|
|
|
|
|
|
|
|
|
|
|
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 25-01 Emergency Ram Air C ¦ 1
¦
Valve
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (M)(O)May be inoperative provided:
¦
a) Air Conditioning Pack 01
¦
remains selected off,
¦
b) Valve is secured open, and
¦
c) Flight is conducted at or
¦
below FL 310.
| ¦
¦
¦
¦
¦
¦
¦ 25-03 Emergency Ram Air C ¦ 1
¦
Check Valve
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (O)May be inoperative open
¦ provided:
¦
a) Air Conditioning Pack 02
¦
remains selected off, and
¦
b) Flight is conducted at or
¦
below FL 310.
| ¦
¦
¦
¦
¦
¦
-------------------------------------------------------------------------------------------------------------------------------------------------------------
Issue: Feb06
Revision: 00
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-MEL
Page 1
MEL (Example)
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 27-04 Forward Cargo
¦ ***
Compartment
¦
Shutoff Valve
¦
¦
C ¦ 1
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦ (M)May be inoperative provided:
¦
a) Valve is secured closed,
¦
b) Fan is deactivated, and
¦
c) Live animals are not carried
¦
in the cargo compartment.
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 1
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ NOTE:
¦
¦
¦
¦
¦ 28-02 In-Flight
¦ ***
Entertainment
¦
(IFE) System
¦
¦
¦
¦
¦
¦
¦
¦
¦
| ¦
| ¦
| ¦
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-3
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
¦ 27-01 Forward Cargo
¦ ***
Compartment Fan
¦
¦
C ¦ 1
¦
¦
¦
¦ 0
¦
¦
¦
¦ (M)May be inoperative provided:
¦
a) Fan is deactivated, and
¦
b) Live animals are not carried
¦
in the cargo compartment.
¦
¦
¦
¦
¦ 27-03 Forward Cargo
C ¦ 1
¦ ***
Compartment Check
¦
¦
Valve
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦ (M)May be inoperative closed
¦ provided:
¦
a) Fan is deactivated, and
¦
b) Live animals are not carried
¦
in the cargo compartment.
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 1
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ NOTE:
¦
¦
¦
¦
(O)May be inoperative open provided
procedures are established and used
to ensure the associated
compartment remains empty, or is
verified to contain only empty
cargo handling equipment, ballast,
(ballast may be loaded in ULDs),
and/or Fly Away Kits.
Operator MELs must define
which items are approved for
inclusion in the Fly Away
Kits, and which materials
can be used as ballast.
¦
¦
¦
¦
¦
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-4
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
Issue: Feb06
Revision: 00
Operator MELs must define
which items are approved for
inclusion in the Fly Away
Kits, and which materials
can be used as ballast.
¦
¦
¦
¦
¦
¦
¦
1) Ventilation
Fan
D ¦ 1
¦
¦ 0
¦
¦ (O)May be inoperative provided IFE
¦ is used in-flight only.
| ¦
| ¦
¦
¦
2) Airflow Switch D ¦ 1
¦
¦ 0
¦
¦ (O)May be inoperative provided IFE
¦ is used in-flight only.
| ¦
| ¦
¦ 0
¦
¦
¦
¦
¦ (M)(O)May be inoperative provided:
¦
a) Affected valve is secured
¦
closed, and
¦
b) IFE is used in-flight only.
¦
|
|
|
|
|
¦ 28-03 In-Flight
¦ ***
Entertainment
¦
System (IFE)
¦
Ground-Shutoff¦
Valve
-------------------------------------------------------------------------------
(O)May be inoperative provided
procedures are established and used
to ensure the associated
compartment remains empty, or is
verified to contain only empty
cargo handling equipment, ballast,
(ballast may be loaded in ULDs),
and/or Fly Away Kits.
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
D ¦ 1
¦
¦
¦
¦
¦
¦
¦
¦
¦
-------------------------------------------------------------------------------
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-MEL
Page 2
190
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 31-01 Cabin Pressure
¦
Control System
¦
(CPCS) Controller
¦
Channels
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-5
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
¦ 28-04 In-Flight
¦ ***
Entertainment
¦
System (IFE)
¦
Vent-Shutoff¦
Valve
D ¦ 1
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦ (M)May be inoperative provided:
¦
a) Affected valve is secured
¦
closed, and
¦
b) IFE is deactivated.
¦
|
|
|
|
|
¦ 29-02 Low Pressure
C ¦ 2
¦
Ground Connection
¦
¦
Check Valves
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 1
¦
¦
¦
¦
¦
¦
¦ (O)One may be inoperative open
¦ provided:
¦
a) Associated Air Conditioning
¦
Pack remains selected off,
¦
and
¦
b) Flight is conducted at or
¦
below FL 310.
| ¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (O)May be inoperative open
¦ provided:
¦
a) Both Air Conditioning Packs
¦
remain selected off,
¦
b) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦ 0
¦
¦
¦ May be inoperative closed provided
¦ Low Pressure Ground Connection is
¦ not used.
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
1) Automatic Mode C ¦ 2
¦
¦
¦ 1
¦
¦
¦ One may be inoperative provided
¦ PRESN MAN FAIL Caution message is
¦ not displayed on EICAS.
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Outflow Valve is positioned
¦
open,
¦
b) Extended overwater flight is
¦
prohibited, and
¦
c) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦ (Continued)
¦
| ¦
| ¦
|
|
|
|
¦
¦
¦
¦
¦
¦
¦
¦
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Issue: Feb06
Revision: 00
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-6
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-MEL
Page 3
MEL (Example)
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 31-02 Outflow Valve
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 1
¦
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Outflow Valve Indication on
¦
MFD operates normally,
¦
b) Outflow Valve is verified
¦
open,
¦
c) Extended overwater flight is
¦
prohibited, and
¦
d) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦
C ¦ 1
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (M)(O)May be inoperative provided:
¦
¦
a) Outflow Valve is removed,
¦
¦
b) Extended overwater flight is | ¦
¦
prohibited, and
| ¦
¦
c) Flight is conducted in an
| ¦
¦
unpressurized configuration.
¦
¦ 31-05 Outflow Valve
¦
Indications on
¦
MFD
C ¦ 2
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ 31-07 Cabin Rate of
¦
Climb Indication
¦
on EICAS
C ¦ 1
¦
¦
¦ 0
¦
¦
¦ May be inoperative provided
¦ Automatic Mode operates normally on
¦ both channels.
¦
¦
¦
¦ 31-09 Cabin
¦
Differential
¦
Pressure
¦
Indication on
¦
EICAS
¦
C ¦ 1
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Cabin Altitude Indication
¦
operates normally, and
¦
b) A table is available to
¦
convert Cabin Altitude to
¦
Cabin Differential Pressure.
¦
¦
¦
¦
¦
¦
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-7
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
¦ 31-01 Cabin Pressure
¦
Control System
¦
(CPCS) Controller
¦
Channels
¦
(Cont'd)
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ May be inoperative provided:
¦
a) Automatic Mode on both
¦
channels operates normally,
¦
and
¦
b) Extended overwater flight is
¦
prohibited.
¦
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Outflow Valve Indication on
¦
MFD operates normally,
¦
b) Outflow Valve is verified
¦
open,
¦
c) Extended overwater flight is
¦
prohibited, and
¦
d) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (M)(O)May be inoperative provided:
¦
¦
a) Outflow Valve is removed,
¦
¦
b) Extended overwater flight is | ¦
¦
prohibited, and
| ¦
¦
c) Flight is conducted in an
| ¦
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦
¦
2) Manual Mode
¦
¦
¦
¦
¦
|
|
|
|
|
|
|
|
|
|
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
|
|
|
|
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Issue: Feb06
Revision: 00
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-8
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-MEL
Page 4
190
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 31-02 Outflow Valve
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 1
¦
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Outflow Valve Indication on
¦
MFD operates normally,
¦
b) Outflow Valve is verified
¦
open,
¦
c) Extended overwater flight is
¦
prohibited, and
¦
d) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦
C ¦ 1
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (M)(O)May be inoperative provided:
¦
¦
a) Outflow Valve is removed,
¦
¦
b) Extended overwater flight is | ¦
¦
prohibited, and
| ¦
¦
c) Flight is conducted in an
| ¦
¦
unpressurized configuration.
¦
¦ 31-05 Outflow Valve
¦
Indications on
¦
MFD
C ¦ 2
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ 31-07 Cabin Rate of
¦
Climb Indication
¦
on EICAS
C ¦ 1
¦
¦
¦ 0
¦
¦
¦ May be inoperative provided
¦ Automatic Mode operates normally on
¦ both channels.
¦
¦
¦
¦ 31-09 Cabin
¦
Differential
¦
Pressure
¦
Indication on
¦
EICAS
¦
C ¦ 1
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Cabin Altitude Indication
¦
operates normally, and
¦
b) A table is available to
¦
convert Cabin Altitude to
¦
Cabin Differential Pressure.
¦
¦
¦
¦
¦
¦
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-7
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
¦ 31-01 Cabin Pressure
¦
Control System
¦
(CPCS) Controller
¦
Channels
¦
(Cont'd)
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ May be inoperative provided:
¦
a) Automatic Mode on both
¦
channels operates normally,
¦
and
¦
b) Extended overwater flight is
¦
prohibited.
¦
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Outflow Valve Indication on
¦
MFD operates normally,
¦
b) Outflow Valve is verified
¦
open,
¦
c) Extended overwater flight is
¦
prohibited, and
¦
d) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦ (M)(O)May be inoperative provided:
¦
¦
a) Outflow Valve is removed,
¦
¦
b) Extended overwater flight is | ¦
¦
prohibited, and
| ¦
¦
c) Flight is conducted in an
| ¦
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦
¦
2) Manual Mode
¦
¦
¦
¦
¦
|
|
|
|
|
|
|
|
|
|
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
|
|
|
|
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Issue: Feb06
Revision: 00
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-8
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-MEL
Page 5
MEL (Example)
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 51-01 Pack Flow Control C ¦ 2
¦
Valves
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 1
¦
¦
¦
¦
¦
¦
¦
¦
¦ (M)(O)One may be inoperative
¦ provided:
¦
a) Affected valve is secured
¦
closed,
¦
b) Associated Air Conditioning
¦
Pack remains selected off,
¦
and
¦
c) Flight is conducted at or
¦
below FL 310.
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦ (M)(O)May be inoperative provided:
¦
a) Affected valves are secured
¦
closed,
¦
b) Both Air Conditioning Packs
¦
remain selected off,
¦
c) Flight is conducted in an
¦
unpressurized configuration.
¦ 51-02 Flow Sensing
¦
Venturis
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦ 1
¦
¦
¦
¦
¦
¦ (O)One may be inoperative provided: | ¦
¦
a) Associated Air Conditioning
¦
¦
Pack remains selected off,
¦
¦
and
¦
¦
b) Flight is conducted at or
¦
¦
below FL 310.
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Both Air Conditioning Packs
¦
remain selected off,
¦
b) Flight is conducted in an
¦
unpressurized configuration.
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-9
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
¦ 31-11 Cabin Altitude
¦
Indication on
¦
EICAS
¦
¦
¦
¦
C ¦ 1
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Cabin Differential
¦
Pressure Indication
¦
operates normally, and
¦
b) A table is available to
¦
convert Cabin Differential
¦
Pressure to Cabin Altitude.
¦
¦
¦
¦
¦
¦
¦
¦ 32-01 Positive Pressure C ¦ 1
¦
Relief Valve
¦
¦
(Including Static
¦
¦
Port and Tubing)
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Outflow Valve is positioned
¦
OPEN, and
¦
b) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦ 32-04 Negative Pressure C ¦ 1
¦
Relief Valve
¦
¦
¦
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Outflow Valve is positioned
¦
OPEN, and
¦
b) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦ 32-14 Positive Pressure C ¦ 2
¦
Relief Valve
¦
¦
Indication on MFD
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ 51-00 Air Conditioning
¦
Packs
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦ 1
¦
¦
¦
¦
¦
¦ (O)One may be inoperative provided: | ¦
¦
a) Associated Air Conditioning
¦
¦
Pack remains selected off,
¦
¦
and
¦
¦
b) Flight is conducted at or
¦
¦
below FL 310.
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Both Air Conditioning Packs
¦
remain selected off,
¦
b) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
| ¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
-------------------------------------------------------------------------------
Issue: Feb06
Revision: 00
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-10
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
-------------------------------------------------------------------------------
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-MEL
Page 6
190
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
------------------------------------------------------------------------------¦ U.S. DEPARTMENT OF TRANSPORTATION
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-11
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 51-08 Water Spray
¦
Nozzles
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦
¦ 1
¦
¦
¦
¦
¦
¦ (O)One may be inoperative provided: | ¦
¦
a) Associated Air Conditioning
¦
¦
Pack remains selected off,
¦
¦
and
¦
¦
b) Flight is conducted at or
¦
¦
below FL 310.
¦
¦
¦
C ¦ 2
¦
¦ 0
¦
¦ (M)May be inoperative provided
¦ affected Spray Nozzle is removed.
¦
¦
¦
¦
¦
¦
¦
C ¦ 2
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦ (O)May be inoperative provided:
¦
a) Both Air Conditioning Packs
¦
remain selected off,
¦
b) Flight is conducted in an
¦
unpressurized configuration.
¦
¦
¦
¦
¦
¦ 61-00 Cockpit Zone
¦
Temperature
¦
Control on Air
¦
Conditioning/
¦
Pneumatic Panel
C ¦ 1
¦
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 61-01 Cockpit Zone
¦
Temperature
¦
Sensor
C ¦ 1
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ 61-05 Cockpit Zone
C ¦ 4
¦
Temperature
¦
¦
Indication on MFD
¦
¦
(SET or ACTUAL)
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 62-00 Passenger Cabin
¦
Zone Temperature
¦
Control
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
1) On Air
Conditioning/
Pneumatic
Panel
C ¦ 1
¦
¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
2) On Flight
Attendant
Panel
C ¦ ¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
C ¦ ¦
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦ 62-04 Passenger Cabin
C ¦ 8
¦
Zone Temperature
¦
¦
Indication on MFD
¦
¦
(SET or ACTUAL)
¦
¦ 0
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦
¦ 62-05 Trim Air
C ¦ 2
¦ ***
Modulating Valves
¦
¦ 0
¦
¦ (M)May be inoperative provided
¦ affected valve is secured closed.
¦
¦
¦ 62-01 Passenger Cabin
¦
Zone Temperature
¦
Sensors
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
Issue: Feb06
Revision: 00
MASTER MINIMUM EQUIPMENT LIST
FEDERAL AVIATION ADMINISTRATION
--------------------------------------------------------------------------AIRCRAFT:
¦ REVISION NO: 3
¦ PAGE:
ERJ-170, ERJ-190
¦
¦
¦ DATE: 08/26/2005
¦ 21-12
--------------------------------------------------------------------------1. ¦ 2. NUMBER INSTALLED
SYSTEM &
¦
-------------------------------------------SEQUENCE
ITEM
¦
¦ 3. NUMBER REQUIRED FOR DISPATCH
NUMBERS
¦
¦
--------------------------------------------------------------- ¦
¦
¦ 4. REMARKS OR EXCEPTIONS
21 AIR CONDITIONING
¦
¦
¦
FOR TRAINING ONLY
Reproduction Prohibited
Chapter 21-MEL
Page 7